In case anyone's interested I have mlbviewer running on slackware-current, it's fairly straightforward.
I have a fairly basic install, running twm as my main desktop, all I had to add were simplejson, rtmpdump and gdata, all available as slackbuilds. It was then just a case of download mlbviewer2014:
untar, cd into the directory and run:
$ python mlbviewer.py
cd into ~/.mlb and add your login details to config then run it again as above and you should be good to go. Video opened in mplayer, audio was fine.
I posted this in the big mlb.tv thread in the fedora forum, just thought I would add it here.