LLVM 3.4.1 was the project's first stable point release in history. While the release overall went well for delivering fixes and some minor improvements, including geometry shaders support in the AMD GPU LLVM back-end, there were a few problems. Aimed to be corrected in the LLVM 3.4.2 release is fixing the build failure with GCC 4.9 and an accidental change of libLLVM's DT_SONAME.
Besides fixing these two main issues, LLVM 3.4.2 will also carry any other LLVM bug-fixes that get proposed in the next few days. Bug-fixes for this next release can be nominated through Thursday while the phase one testing will be from 16 to 23 May, and on 25 May will be the release -- assuming additional testing isn't needed.
AMD's Tom Stellard is again coordinating the release and you can find out more via the 3.4.2 release plans.