I suspect the Ottomans are carefully neutral - not allowing materials that could effect the war to pass through the Straits. The fact that this weakens the Ottoman's number one enemy in the world is just a tidy coincidence.
I can't see it lasting though. Both world wars set a pretty clear record for the rights of neutrals. You could be be neutral as long as you didn't matter and weren't in the way.
The Ottomans will come under tremendous pressure from the British to open the Dardanelles to Entente shipping. It's something that would make a profound difference to the war effort so they're not going to let it go. The Central Powers, meanwhile, can't really offer the Ottomans much of anything, once the war has begun in earnest. And it isn't as if they can use the threat of force: "If you don't join us, we'll stop pushing on the major fronts, concentrate on Serbia, invade Bulgaria, and then you'll be sorry."
I'd expect the straits to open some time in 1915 in exchange for concessions to the Turks. I just wonder what they'd be....