Earlier versions have been an essential part of my 'conversion toolbox' and I see no reason why I'd want to exclude it. I'll chalk it up to this being a beta version. I find it working with other apps but MPEG Streamclip seems to have trouble playing the MPEG2 file (although it does seems to convert the file to H264/AAC in a.
Seems to be an issue using the MPEG2 component from Apple.