No it doesn't make sense. With all the problems that they are facing why would they waste time on something that is way out side of their core competency and skill-set?
Why? Desperation... and they certainly seem to be dishing out a lot of that lately. I do hope this is just a false rumor, though. RIM is starting to feel too much like that weird kid in elementary school that everyone picks on to the point that you stop because you feel sorry for him. My brother-in-law just got a Droid Pro after using Blackberries for years and he LOVES it. I didn't have the heart to tell him what a mediocre device he just bought, but the fact the he was so excited about a mediocre device after moving on from Blackberry says volumes. RIM is done.
I don't think it makes sense at all. They should just focus on getting their act together. They need to focus on one thing right now and make that one thing very very good. If they are really working on this, I think that they're just spreading themselves too thin and will fall for sure.
Sounds like another nail is being pounded on the blackberry coffin.
I can see a device that projects the Playbook and Blackberry content to TVs, projectors, monitors, etc, but not a full-on AppleTV-like experience.