Napoleon is routed back to France, looking like an overly ambitious fool considering his "crown self as emperor" scheme, the Holy Roman Empire is not dissolved (albeit it evolves into an institution similar to the German Confederation), and the terms of France's defeat would certainy be different from OTL's.
If the Dutch break off from the French embrace, there's a possibility of them keeping South Africa.
With no Peninsular War, the Spanish Americas may evolve into a commonwealth of autonomous states. Similar thing for Brazil.
With less continental distractions, Britain will be able to better deal with the USA if the 1812 War still happens. That is, if it still happens, because the British will surely look a bit scarier.
Austria, rather than Prussia, will become the main patron of German nationalism, if it still develops.
Russia might get more concessions from Qajar Persia in the 1804-1813 War.
The Third Polish Partition borders remain in place.
I'm not sure about Italy, but it is possible that it'll fall under Habsburg influence.
Lots upon lots of butterflies.