Grr.. it's not that this is a bad question, but that there are still so many misconceptions flying around. "Home sucks at networking," "Home doesn't have NTFS," etc. Here are the notable features that Pro has, which Home does not, along with my commentary (I have both, by the way).
Encrypted File System - Pro's EFS can encrypt your files so that a burglar cannot read your files after stealing your hard drive. It also produces at least one post per week about someone who permanently lost GB's worth of data. I suspect a lot of people have delusions of grandeur about the importance of their pr0n. Note that both versions will let you keep folders private so that other users cannot access your files within the OS.
Group permissions for shared files - Pro lets you limit access to shared folders to specified groups. If you're a typical home user with one or two accounts on the machine, this is pretty pointless. See delusional comments above. Home will still allow per-group permissions on reg keys, so that you can tweak programs to allow a limited account proper privileges.
Domain support - Pro allows you to log into a Windows domain. Which I'm sure everyone has at home...
SMP - Pro supports multiple processors (just 2, I think), Home does not. This is certainly a valid concern if you've got the hardware.
Remote Desktop - Pro allows Remote Desktop connections. Cool in theory, but few people actually use it...
Automated System Recovery (ASR) - some kind of automated recovery tool, don't know much about it. Entirely different than System Restore, which both versions support.
Dynamic Disks - for software RAID or online disk expansion. Software RAID is arguably useful, but you'd be better off buying a card to handle this anyway. If flamers think Dynamic Disks have anything to do with SCSI performance, go reread the SR forums for a while.
Home is fine for the vast majority of home users (funny, huh?), whether self-proclaimed "power users" or not. Apart from SMP or possibly software RAID, the only reason to get Pro at home is if you're studying for an MCSE or similar and need domain logon capabilities to test things out.
Flame away...