Although I do not buy into the "bulwark against communism" theory that some here seem to have, if you remove nazism as a major force in the german political landscape in the 20's and 30's, then butterflies could lead to a stronger influence by the communists. This is not necessessarily a direct result of no nazism, but more like a side effect.
That being said, I believe that there is a good chance that in the absence of the nazi's and the charismatic austrian corporal, there is a very good chance of a pseudo-fascist movement which is very military centric and focuses on restoration of the kaiser, or some other form of monarch. A revanchist monarchist regime could just as easily use the "stab in the back" myth to their advantage, as well as channeling hatred at the entente for versailles. The up-side(for them anyway) is that such a movement isn't bound by the insanity that the Nazi party was, it could be antisemitic, but would not likely be genocidal or focus on racial ideology to anywhere near the degree that the nazi's were. This eliminates the atrocities which turned the populace of eastern europe against them, and more or less precluded peace with the west. this also gets rid of the idea of "jewish" science as well.
However any such movement may also be handicapped by the aristocracy being in its leadership roles and thus be less meritocratic. This could severely hamper any military operations due to the presence of incompetent officers that cannot be removed from command due to their family name.