Not that many useful things - good if you have a Home Network or indeed a Network in itself. Pretty lucrative if you're the Admin of a School Network and you need to buy the rights to 200 Windows 2000 Licences; when you could go to your superiors and say you've got Windows XP for their machines and it will cost half the money! And then you can pay the £20 and take the, I don't know, £750 it would cost otherwise!
No, really, what I like is the Encyption - although I have no use for it - and the User Acocunt Tools. I don't know whether it works on Home; you can try it for me if you want, but if you put 'control userpasswords2' in the Run Prompt then a nice Windows 2000 Pro Style User Accounts Panel which is nice. Also, when your friends or anybody comes round and you switch the computer on, its nice to see a Windows XP Professional Boot Screen!