I'm working on the necessary sslsplit support here: https://github.com/fix-macosx/sslsplit

I've just about wrapped up support for correlating connections with the local responsible program (see branch macosx-process-info); I also need to put some thought into how to handle non-TCP traffic.

I'll be posting Yosemite setup instructions later today; my plan is to collect a corpus of data from a default installation. One thing I could really use help with is providing a web-based visualization of that data.