I rip using Handbrake at the highest possible settings, if that's too large then I'll compress the file using ffmpegx and then fire it over to the 360 via Connect360.
This is all on a 1GHz TiBook by the way, but I'm sure the same processes apply to a MBP.
I export the file as whatever Handbrake gives me, ffmpegx will convert it to .mp4 and I just use the default settings in both Handbrake and ffmpegx and that seems to work out fine.
I used to use visual hub to convert files to the necessary WMV format, but I guess that was with an earlier version of Connect 360. Woohoo!! I didn't know there was a new version out that supported mp4!!
I don't have any solid evidence, but in the settings there is an option for sharing video and audio podcasts... I have mine unchecked so I don't know if it works.. I'll give it a try and post back if it works.