http://boardsus.playstation.com/t5/PlayStation-Network/Anyway-to-watch-MLB-tv-on-ps3/m-p/28581318
Yes. You can find the mms:// feed with URL Snooper. Then you can stream it with TVersity. I tried everything and this works. But you have to be quick, the mms address goes dead after 1 minute. So you have to get it streaming to the PS3 within that time. Sometimes it takes a couple of tries.