Obfsproxy TBBs don't work on Mac OS X 10.7.4 and 10.8.1
The "OSX (10.6 & 10.7) 64-bit Obfsproxy Tor Browser Bundle" from https://www.torproject.org/projects/obfsproxy.html.en breaks on OSX 10.7.4 and 10.8.1.
Aug 29 08:55:39.582 [Warning] Our communication channel with the managed proxy 'obfsproxy' closed. Most probably application stopped running. [...] Aug 29 08:55:40.585 [Warning] We were supposed to connect to bridge '(scrubbed)' using pluggable transport 'obfs2', but we can't find a pluggable transport proxy supporting 'obfs2'. This can happen if you haven't provided a ClientTransportPlugin line, or if your pluggable transport proxy stopped running.