Visual Studio RT
It would be nice to be able to use Visual Studio on Windows RT. Ideally this would enable you to develop in C#, F#, C++, HTML etc on a Surface Tablet or other Windows RT device.
It would be nice to be able to take advantage of TFS and GIT and be able to develop on Windows RT. While some applications may not be able to be tested on Windows RT such as WPF Applications etc others such as Modern UI Apps could be developed or tweaked on the device they are designed for.
This would make doing work on Windows RT devices even more of a reality and make coding away from the desktop easier.
டினோ சுரேசன் commented
Without Visual Studio for ARM, no "productive" Windows RT tablet for me.
This is literally the only thing that's holding me back from getting any sort of RT tablet. I would love to get a Surface...but without Visual Studio, there's pretty much no practical reason to.
I would get a Surface RT if it had Visual Studio available
Thomas Prioul commented
Visual Studio Express should be available via the Windows store for Windows RT devices.
I also think it would make more sense to develop apps directly on the device they are designed for, and it gives another point to prove that Windows RT can be productive!