First off brilliant topic idea its a most interesting question.
Personally I think it would of varied wildly depending on the political situation of the respective empires.
Forced nationalism on Europe and Asia minor by the United States and the French doomed the countries they created to unrest for decades possibly even centuries to come, empires are places for the most part where people can peacefully co-exist regardless of ethnicity and religion. While nation states with their unstable democratic governments are much more prone to ethnic and religious violence, where a nation state would fall apart after unrest in a particular province or country sized area an empire would send in the troops gathered from around the world to maintain order.
Nationalism is a rather new idea in the grand scheme of the world and one that we take for granted today. If not for the rhetoric of Woodrow Wilson proclaiming that every one should be like the United States as a liberal democracy, the world we live in today may of been a much more peaceful place. Of course the French were more than happy to carve up the old European empires as to eliminate rivals for the future and the British were indifferent having no real stake in the politics of continental Europe.
It seems to me that WW1 was an accident a tangled web of alliances turned an assasination of one man into war that ended up encompassing the entire world that no one wanted to fight in the first place. So I think there wouldnt of been a great deal of animosity amongst the empires post war so I think continued peace could of been a likely possibility as long as territorial concessions and reparations if any were fair.
Germany - Would of survived to become an economic super power much like the Germany of today only with more territory so therefore one would imagine more economic and military might. Germany could of become the manufacturing centre of Europe in the late 1920’s and early 1930’s as opposed to it taking till the mid 1950’s. The Kaiser was reasonably well liked until the surrender at the end of WW1, had the Kaisers successors been good rulers I have no doubt in my mind that its a reasonable possibility that there still could be a Kaiser in control of Germany.
British Empire - Survived long after the other empires were destroyed, had the British not been so utterly bankrupted by WW1 the empire would of lasted into the forseeable future, Only with the massive debts of WW1 and WW2 and American interference in Britains empire did it all finally fall apart in the late 1940’s and 1950’s. With a strong economically independent Britian the empire could of lasted long past this very day i’m making this post. Also if the spirit of nationalism had not of been ignited in Europe the British would not of had to worry so much about independence movements from throughout its empire.
Russia - Is a very interesting one, only by sheer luck did the Bolsheviks actually seize power in Russia against the forces of the White armys. If the war had of ended satisfactorily for the Russians the Romanovs would of continued in power for at least the next couple of decades probably more and depending on the ruling style of the successors to the Tsar and the living standards of the average Russian. Had the Red Revolution even taken place in 1917 with Europe at peace the entire might of the armys of France and Britain could of been brought to bare against the Bolsheviks, the key though would of been the survival of at least 1 Romanov to become Tsar when the dust settled and someone to rally around at that time of civil war.
Ottoman Empire - The Ottoman empire was economically finished a long time before WW1 so the forces of Arab Nationalism would of torn it apart before too long, probably only lasting for an extra 5-15 years from the date it actually collapsed in reality. The seeds of revolution were alredy sewn long before the Ottoman loss in WW1.
Austria-Hungary - Was on its way out before the war too, the forces of ethnic and racial hatred was already tearing the empire apart. The assination of the Arch Duke only being a small symptom of a much greater problem of cramming 15 different ethnic groups into an empire that didnt have the economic or politcal stability to hold it self together. I believe it would of been much the same story as the Ottomans a 5-15 year time frame where everything would of fallen apart as nation states formed and Germany would of annexed Austria much like it did in the 1930’s.