I sure wonder what it’s bundled with, considering how bloated iTunes is. I’ve already had the experience of reinstalling iTunes twice for someone and it’s not as straight forward as it sounds. Installing iTunes is easy. To reinstall iTunes, you must uninstall iTunes, followed by QuickTime, Apple Software Update, Apple Mobile Device Support, Bonjour and Apple Application Support in this sequence only before reinstalling iTunes (more info here), with the whole process taking 30 minutes for a typical PC from a few years ago.
I highly doubt Apple will discontinue Windows XP support anytime soon for iTunes, unless they have some clever way of luring people into buying a Mac as an upgrade from their obsolete XP PC.
As for the iCloud - there is a workaround - Just install Windows Vista/7 in Virtual PC and run iCloud from there. That’ll also keep it off the main OS.