And, for the record, even 50" is way too small.
I have a 52" in the living room now and a 120" projection in my theater room. There is no place for some tiny Apple televion, and the 50", while not tiny, would be a downgrade for a lot of normal people, much less Apple people.
Do bear in mind though that a large segment of Apple's target market do not live in Texas-sized houses…
I live in the UK in a decent sized house and believe me a 52" screen is really far too big. Not even talking about your lottery-winner style theatre room with 120" projection.
There is plenty of market for smaller sizes — outside the US.