Let's see:
Russia, for its part, will be invading all over the place. Persia, the Caucasus, Manchuria, supporting Austria-Hungary in the Balkans, etc, will tie up Russian manpower, but it will also tie up huge amounts of Entente manpower. Japan is in for the fight of its life, and will have to do a lot more than just snag a few German outposts. They will probably get some support from the British to make up for it.
The Ottoman Empire is pretty much toast. Not only do they have the Caucasus to worry about, but as Russian invasion becomes increasingly likely, Greece, Serbia, and Bulgaria all will join the Central Powers (Greece due to claims on Turkey, Bulgaria due to the same and alliances, Serbia because it is pressured into doing so.) Again, British troops might prop the Ottomans up in its Arab territories, but Constantinople (or should I say Tsargrad) is gonna be captured, and when they lose in the Caucasus the whole front will collapse. I expect Russia to grab Constantinople itself, Bulgaria to grab the rest of Thrace, Greece to grab parts of Western Anatolia situated around Smyrna, and the Armenians to join up with the Russian Empire, and that's only to the Central Powers themselves. The whole Empire is leaving one way or another, though if Britain plays its cards right several territories may just be under their influence or control.
Austria-Hungary has the good fortune of not having its Officer Corps decimated at the beginning of the war, so ITTL they're going to be far more than dead weight. With only the Italian front to worry about (although they'll assist in the Balkans), they'll slowly but surely start pushing back the Italians, eventually forcing them out of the war. Italy had an incompetent army that an Austria-Hungary not weakened by OTL's 1914 could defeat without too much trouble. The Habsburgs will probably take a nice slice out of Italy, possibly even including Venice, as well as some reparations. Once Italy is gone, Austria-Hungary can reinforce Germany in the West if needed.
France will be bloody, and Germany will have its fair share of trouble defeating them. But they will, because they have superior artillery, manpower, military doctrine, and industry. Paris will be captured near the end of 1915, with Russian and Austrian troops participating somewhat. Belgium and the Netherlands will both either be invaded or forced to become essentially German vassal states.
By 1916, the Three Emperors will reign supreme over Europe, enforcing harsh peaces on the other powers. Look to the Septemberprogramm to see how Germany would treat France (and Belgium), while they'll be able to get their African colonies back by giving up the huge chunk of French territory they have captured. Britain will get off fairly light, although they'll be humiliated and shown to not be able to protect their allies. The British Empire will also lose not even a square mile of land, even gaining a few territories off of Germany in the form of Pacific Islands. The French colonial Empire will lose a lot of its land in Africa to Germany in exchange for peace.
Japan may or may not get out of this alright. They will have to face the Russian bear on the mainland, and this Russian bear may eventually receive German and Austrian support. Russia is going to want revenge for their earlier war, and they'll get it. Japan will lose Manchuria to Russia and Korea to "independence" (really a puppet of Russia), although they'll keep what they took from Germany. After the war, they'll align themselves strongly with Britain.
In Persia and Central Asia, Russia and Britain will square off. Due to geographical difficulties, I foresee this just being a stalemate, but it's going to be a stalemate that drains British resources. It will also spur on Indian independence, because they will be the soldiers Britain uses to defend their interests.
In Africa, German will get a nice big colonial Empire post-war, despite Britain doing everything it can to stop them (you can only tell France to not hand over their colonies so much when German troops occupy their homeland, after all). They will lose what they lost IOTL to South Africa, as well as probably Togoland, but the Belgian and French Congo as well as French territories outside of West Africa and Djoubouti will make up the new German African colonies. In many ways this is a plus for Germany: They lost some of their more expensive colonies and exchanged them for more profitable ones.
Europe is now at peace, with France, Italy, and Turkey beaten down dramatically. Germany dominates Western Europe, converting Denmark, the Netherlands and Belgium into what is essentially vassal states and annexing portions of each country. France has lost many industrial regions to Germany, including a major steel-producing one, and is going to be reeling from the reparations leveraged upon them even worse than OTL's on Germany. Italy has been soundly defeated, and I could see them losing parts of their colonial Empire. Once this happens, Germany or Britain could intervene to pick up their lost colonies. For the sake of simplicity, we'll say Britain takes over East Africa while Germany gets a protectorate in Libya.
Austria-Hungary expands its influence over Italy, and ethnic tensions are going to be a serious problem. However, self-determination never really got that far off the ground TTL, so with suppression and German assistance, they'll keep their Empire and hopefully reform.
In the Southern Balkans, Greece and Bulgaria now both have substantial Turkish minorities, although population exchanges might make that work a little more. I expect they'll stay allies that are friendly towards both Russia and Germany and focused on keeping Turkey from making a comeback.
In Eastern Europe, tensions between Germany and Austria-Hungary and Russia will cause a bit of a rivalry between Berlin and St.Petersburg to form, for much the same reasons as IOTL in the early 1900s. Austria-Hungary will obviously stay on Germany's side, as will the German vassals of Belgium, the Netherlands, and Denmark, but a revanchinist France and Italy will align themselves with Russia in the hopes of getting revenge and recouping losses. Britain will at first stay neutral, trying to play the two off each other.
Russia will have annexed much of the Pontic and Armenian (historical Armenia, mind you) regions from Turkey on flimsy claims. What's left is truly going to be a rump Turkey. I imagine in the Middle East there will be a Kurdistan under the control of Russia, while Britain/France (probably just Britain, anything would really just be a consolation prize) control Syria and the Levant. Arabia also has Western-influenced states pop up, while Iran just tries to stick together (It's going to fall into the British sphere of influence just out of self-preservation).
In Asia, the balance of power will have changed dramatically. As I said before, Japan and Britain will strengthen the Anglo-Japanese alliance, fearing for Russian domination of Eastern Asia. Russia will probably end up sticking its nose in the Chinese civil war, which will further build up tension. As time goes on, Britain is going to decide it can live with Germany, but not with Russia. A conflict may or may not come eventually, between a British-Japanes-German-Habsburg alliance and a Russian-French-Italian alliance. But that's really too far into the future to comment on what might happen.
Wow. I wrote a lot.