Here's my wish list:
HUBS
- Add SkyDrive hub
- Ability to add custom hubs as a solution for grouping like-apps
MAIL
- Option to change background color to black
MESSAGING
- Ability to send video via MMS
- Options to Save Picture or Save Video to SkyDrive
- Options for the long press menu on any thread: Call, Call with Skype, Copy to SkyDrive, Forward, View Profile
- Long press menu option for any single text: Copy to SkyDrive
- Add offline messaging for Facebook conversations
CAMERA ROLL
- Ability to multi-select for deletion, saving to SkyDrive, e-mailing
MUSIC + VIDEO
- Rename to Media Center to be consistent with Windows desktop
- Add E-books category
- Long press menu on music track: Bing for Lyrics, More from this Artist, Set as Ringtone
- Ability to save MP3, WMA, WMV, MPG, WAV, MIDI and AVI direct to the phone
PEOPLE
- Add field to add IM contact information
- Add ability to message users of other IM services
APPS
- Mobile version of Writer
- Mobile version of Movie Maker
- Mobile version of Photo Gallery
SETTINGS
- Ability to adjust brightness more precisely with a drag bar
- Ability to opt in to a mobile version of Family Safety to control child accounts and associated permissions texting, web browsing, etc.
- More theme colors
- Different volume levels for alerts, ringtones, etc.
- Long press on power button to present options for: Shut Down, Restart, Airplane Mode On/Off, Wi-Fi On/Off