GNU Automake 1.10.1 was released yesterday, finally featuring LZMA support, meaning you can now make Automake create .tar.lzma files. LZMA usually compresses better than bzip2 and also decompresses faster. To create .tar.lzma files for your projects you have to modify AUTOMAKE_OPTIONS in the related Makefile.am file:

AUTOMAKE_OPTIONS = 1.10.1 dist-lzma

Would be great to see Automake-based projects adopt this feature in the near future.