Interesting question. In many ways, a more interesting question than "what if Germany had won WWII?" (well, for me, anyway).
Germany would have invariably seized more territory. Some to the East possibly around Lodsch and Kalisch (in present day Poland), and to the West possibly in Lorraine. New, pro-German, states similar to those formed in the Treaty of Brest-Litovsk, would form; likely German-led Polish, Baltic, and Finnish monarchies (as per Brest-Litovsk). The Germans were also interested in forming a Ukrainian state, a republic in the Caucasus, and a Tatar republic in Crimea. This was according to their Mitteleuropa
Plan. These would be ostensibly allies of Germany, although they would eventually be targets for colonisation and Germanisation. The German Reich would also be likely to seize Belgian colonies in the Congo, creating a more contigious Mittelafrika
colony for themselves, although I'm not too sure how interested they were in British colonies.
Unfortunately (as I am rather enamoured with Austria-Hungary
), Austria-Hungary may not have survived much longer as a state. It would have had to implement something along the lines of the plans for the United States of Greater Austria (which were championed by Archduke Franz Ferdinand), giving equal self-governance to each ethnic group. However, the Hungarian administration would have opposed this, as they enjoyed their equal status with Cisleithania, and would have lost masses of territory and a lot of bargaining power if the Dual Monarchy were to become a trial, or even plural one. In the event that it survived at least winning the war, what Austria-Hungary may have demanded would be somewhat complicated by the political and social climate within the country. Elements within the Austrian administration were enthusiastic about the chance of regaining Lombardy-Venetia from the Italians, whilst the some in the Hungarian administration would have wanted to get land from Romania and Serbia. However, people in both governments were suspicious (reasonably so) about annexing any more territory - it would be foolish to add even more Slavs to the Empire, even further tipping the balance against the Germans and the Magyars.
Whilst the Bulgarians were interested in parts of Serbia and Dobruja, I don't think the Ottomans could have really got a great deal out of the war. They possibly could have regained parts of the Caucasus, but, as they were already the 'Sick Man of Europe', their chief aim was probably just to continue their existence as a state.
Another point of interest would be its effect on world politics. We are used to Liberalism (in the European democratic and capitalist sense) vs. Communism being the post-WWII consensus, but if Germany had won WWI, would it have liberalised much politically? The olde-worlde junker
-style Conservatism of Germany could have had increased credence, and survived a lot longer than it has in reality. The relationship between that and the Soviet Union would have been interesting, as would the German Empire's interactions with the USA. Would we even see a future American hegemony in the case of a German win?
Italy would have been further humiliated, with no Italian-speaking lands gained at all, so we can't assume that Mussolini, or someone similar, would not have come to power there. Whilst I don't think Fascism could have gained much credence in Britain as a result of losing the war (unlike Germany, Britain had an established history of democracy and Liberalism), it would be interesting to see what would have happened in France. I don't think for one minute that they'd have caused genocide, or started a war as damaging as WWII as Hitler did, but ultra-right wing groups and early Fascists in France, similar to the Legitimist (politically, as they were counter-revolutionary; they were Orléanist in terms of succession) Action Française
or Valois' Faisceau
, could have gained power (though that is pure conjecture on my part). This would mirror Hitler's rise to power in the post-war Germany of reality, though I doubt they would be anything close to the Nazis - probably nothing much worse than a Latin American dictatorship (and I am aware that these were no picnics).
Whilst I don't think Hitler or the Nazis in particular would have come to power, I wouldn't entirely rule out something similar happening. Some of the ideology was already there, in the form of the Conservative Revolutionaries, and it is possible that the German Empire would have faced increasing pressure to liberalise, whilst at the same time being threatened by Communism.
Even then, I don't think that the Holocaust would have happened. Providing the Austro-Hungarians were willing to listen to ethnic concerns and offer Slavs equal legislative and executive status within the Empire, the unifying, single Habsburg monarchy encompassing Mitteleuropa could
have survived, possibly avoiding some post-war issues of ethnic conflict (such as Germans and Magyars being expelled from Eastern Europe following WWII). So, in some ways, it could have been a better world had the Central Powers won.