That's interesting - I knew the frontend wasn't going to work on XP, but I didn't know the CRT was ditching it too.
The .NET outputted binaries will still work on XP (they use the framework CRT, not the VS CRT) and you'll still be able to use old versions of Visual Studio both on and for XP. If you're targetting XP why do you need the latest and greatest compiler? VS2010 end of lifes a long way into the future.
Also the end of life for XP has already passed - mainstream support for XP expired on April 14th 2009, so if you're still using XP, expect it to deteriorate and for Microsoft to not support it. The 2014 date is the end of extended support.