I asked for these features in a past thread:
1. Resolution Independence (It actually got worse in Snow Leopard.)
2. System-wide Touch (Where are you? Windows 7 has it built-in.)
3. ZFS or new Apple file system (Time Machine needs you badly.)
4. Marble (We need a unified UI.) [Marble has since been confirmed to be Xcode 4, not a unified UI for OS X.]
5. Original concept of Stacks as Virtual Folders (Bring back the Stacks feature that was originally demoed where Stacks acted as a virtual folder for any set of random items in the Finder. Let saved Spotlight searches become Stacks also.)
Other wishes:
1. Revamped Display preferences with built-in Plex-like overscan adjustment for HDTVs and better resolution detection. (Snow Leopard has made an attempt, but more work is needed.)[This has been added for certain videos cards including the latest MacBooks and the new Mac mini although it’s not as good as Plex’s.]
2. System-wide Media Sharing. (Using the Sharing preference pane instead of requiring iTunes or iPhoto to be open. DLNA certification with built-in media transcoding would be nice also.)
3. Bring back QuickTime Pro X, drop the ability to install QuickTime 7. (And drop the $30 charge for Pro X.)
4. Refine the 3D Dock so it doesn't take up as much space both vertically and horizontally.
5. Fix iCal so you don't have to launch Inspector or Get Info to adjust events.
6. Put contextual services back like the Snow Leopard beta seeds where they mimic the new Services menu complete with organization and application icons.
7. Officially support AirPort Extreme AirDisk drives as Time Machine backup drives with built-in formatting accessible from AirPort Utility. Add disk repair functions (from Disk Utility) to both Time Capsule and AirPort Extreme to fix minor disk problems with internal (Time Capsule) and external (AirPort Extreme) AirDisks.
8. More integration between iCal, Mail and Address Book (Dare I say combine them a la Microsoft Outlook?).