I'm reading here:
On Apple.com it says:
Could someone check this out? It would be nice to sync it without having to connect it at all, i.e. completely wireless.iOS 5 devices will be able to sync with iTunes either wirelessly (when connected to a power source) or through the usual USB cable
On Apple.com it says:
The way I read it, it simply automatically starts the sync as soon as you connect it to a power source (which is logical), but it doesn't say that you need to have it connected.Wirelessly sync your iOS device to your Mac or PC over a shared Wi-Fi connection. Every time you connect your iOS device to a power source (say, overnight for charging), it automatically syncs and backs up any new content to iTunes. So you always have your movies, TV shows, home videos, and photo albums everywhere you want them.