If you plan to attend Apple's Worldwide Developers Conference (WWDC) in June, and are interested in LLVM, please consider attending the "New Compiler Technology and Future Directions" session.
From the recently updated WWDC page:
"Xcode 3.1 introduces two new compilers for Mac OS X: GCC 4.2 and LLVM-GCC. Learn how the new security and performance improvements in GCC 4.2 can help you produce better applications. Understand the innovations in LLVM-GCC, and find out how you can use it in your own testing and development. Finally, get a preview of future compiler developments."