We've been focused on first class Windows support since day one. The only major issue for LLVM itself that I'm aware of is the lack of PDB debug info, which is less of a problem for Rust because the system debuggers don't debug Rust in the first place. Most of the clang problems for Windows that I'm aware of relate to all the MSVC extensions in windows.h, which is not a problem for Rust as it doesn't use system header files.
I don't know if you'll see this, but I've been wanting to contribute to Rust for a while now. I've checked through the Github issues, but it's not really clear to me what I should do if there's one I think I can do. How should I approach it?
The PS3 and Xbox360 won't go away in the next 5 years. The issue is not so much PPC (which should get support anyway), but various other silly things, like needing to rely on certain interactions between the compiler and runtime library. This is not a huge issue, but any extra bump will deter people from trying.
And indeed it's possible to have an alternate toolchain, but lots of work that is best avoided most of the time.
