@jbizzy, Kodi doesn't seem to support this add-on, XBMC still seems to work, Spring training games starts this Monday the 3rd, so we won't know for sure if this add-on works as it did last year (2014)
Being a MLB.TV prem. member myself, I used the app from XBMC, when possible, but having a smart TV, roku, apple tv2 and fire TV I have a few different option on how to view MLB.TV including via my laptop. (HDMI from laptop to TV is OK, but not the best option) since upgrading to Kodi, I might on Monday wipe my Pi and reinstall XBMC just to see how it runs. Also there is a member at the .org that post a zip with a MLB update this is supposed to work on Kodi, again we won't know for sure until Monday.