MLB.TV hidef not supported on Mavericks (OS X 10.9)

According to the MLB.tv site, OS X 10.9 isn't a supported device - and this is still true today, opening day of the season. Seems amazing they haven't figured this out as the OS has been out quite awhile now. (The NextDef plugin required has issues)

And here I was all set to give them my money, but as my macs are both at 10.9, I can't watch hi-def. Seems like quite a boondoggle!

(I know, first world problems, etc) (alos, I'm not the poster of the article above)