I think Apple has to focus .Mac a bit more into a few perks and mainly services. It should gear itself more towards families, "buddy" groups, and people who want to communicate better between home and work (and mobile computing) who could take better advantage of .Mac services via the internet.
Top ten ways to improve .Mac:
10. improved Backup (with more "smart" folders, compression, etc.)
9. combine with more "personalized" AppleCare and training/support pages
8. improved public folder/file sharing service (FTP, iDisk Utility, SMB, etc.)
7. improved Homepage updating, site organization, and create-your-own template features
6. something like newgroups?
5. extra perks for the iApps: tunes, stock pictures, sounds, movie clips, etc.
4. throw in Disk Utility with some extra perks for cleaning up and administering the computer?
3. partner with someone with special Hot Deals or other types of purchasing (including third-party) discounts. More than just small game discounts. Make a "coupon book."
2. offer free previews of upcoming software releases from developers-- generate revenue from third parties this way.
1. Make OS X release of the classic Puzzle!