No idea what they changed.
Well, they updated both QT and iTunes.
They broke something in QT, so previous QT Pro version won't work (ex 4, 5, 6). So you have to have a QT 7 Pro key.
As far as iTunes, not sure.
But...
What does this take a 80MB download (55 itunes and 25 QT?)
No modular patching, etc. Sorta lame you have to download the whole beast and reinstall every time there is an update.
Sure, not biggie over fat pipe, but from hotspots (or EVDO) is can be a pain.