Would apps developers be able to build iCloud into their games/apps so as to allow us to sync saved games and data between idevices? For instance, i do not want to play infinity blade twice on iphone and ipad.
That is only just like restoring from a traditional backup and doesn't require any changes in the app/game, it will be possible for apps to save their actual data to iCloud though and that will then sync across all your devices automagically but that requires the apps to be updated & released for iOS 5 once it is available.
Some apps try to do this manually at the moment with Dropbox or iDisk but those solutions aren't very robust and prone to failure plus require setting up on each device per app.