I could see the Austrians 'cocking this one up', so to speak, but then again, they could just as easily bring in the Russians to help them, as they did IOTL. Now, there was fairly strong sympathy towards the Hungarians on the part of the Russians; one story I read, in a book about the Russian Army under Nicholas I, mentions that Russian and Hungarian officers would have dinner parties, and the toasts would start out, "to Russia", "to Hungary", etc. As the officers became more drunk, the toasts would devolve into, "to the ruin of Austria!"
However, Nicholas I wasn't a big fan of liberal ideology/ideas (they had nearly led to his being overthrown in 1825, just after his coronation as Tsar no less!), and given the close proximity of Hungary to the Russian frontier, Nikky wouldn't tolerate it. Not too mention, Russia got a fair amount from helping the Austrians (control of parts of the Danube, greater influence in the Balkans), so I don't see why the Russians wouldn't intervene (although admittedly, I'm no expert on the 'Peoples' Spring' of 1848
).
I could see the Austrians screwing up somehow, and if the Hungarians coordinate their efforts better, it will undoubtedly help their cause. But once Ivan gets involved, well, I don't really see the result being that much different from IOTL.
But that's just my 2 cents...