Stability would be good lol.
I'd like to see a mode just for administration tasks. For example to get to the actual nitty gritty of the system I can only see two ways of getting there right now. Going into the desktop app and digging through there or going to settings, even more settings blah blah blah. To get to anything you have to jump through hoops and i smell trouble. What if they made ONE place password protected where you could find the MMC, command line, advanced setting and recovery options? ONE place. Someplace where it would be easy to get to should the metro interface crap out. Even the f8 option is limited. Ive not seen any safe mode or variety of it per say, It looks like if one thing goes wrong it would mean forever worth of navigating to fix it.