One of my biggest issues with Windows Phone is once more highlighted, namely backing up and restoring data. "...we also want to see the ability to do a full backup and restore of your phone, using your PC, the cloud, a spare SD card or anything else" Branscombe and McCann write, and I'll second that opinion.
Perhaps three columns of live tiles?
It's also worth repeating their thoughts on SkyDrive, and the idea of putting in place some granularity to the access offered through the API:
We'd also like better security for what apps can do on your SkyDrive; once you give them access they can read, write and even delete files. They need to do that with the files that the app creates, but nothing (apart from the Windows Marketplace approvals process) is stopping an app from changing or deleting other files. Keeping the files you create with one app in a sandbox so you can't see them in another app is proving inconvenient in iCloud, but a developer doesn't have to be malicious for a programming error to accidentally delete files.
Six more ideas from Branscombe and McCann for inclusion in the next version of Windows Phone, along with the naming issues, can be found here.