I'm pretty sure our sets will be able to utilize digital TVGOS (ATSC Slicing) being broadcat by CBS based on the TVGOS base firmware version and the fact we can enable ATSC Slicing. I have been following these two threads, but haven't yet tried to force my set to use a digital channel for TVGOS.
I finally checked TVGOS on the Mits and all is well with the listings...although it is much slower after the Cablecard. I also noticed the Mits it was running the same version of TVGOS as on my Sony DHG-HDD500 (08.06.44). I found this to be a little odd since I recall the sales person telling me it ran v9 when I purchased the set in Feb '07. Anyway, both devices are currently using local analog PBS station for TVGOS data, but I have forced the Sony to use the digital CBS station (with limited success) in the past.
Since my replacement lamp just arrived, I was thinking of trying to clean the lens while I am at it. Of course, the one thing I dislike about TVGOS is how long it takes to edit the channel lineup.