[pyre]

If all you want is HiDef Planet Earth... it was released on HDDVD. You could probably get a copy and a player for cheap.

[kdw]

I actually had one. I switched to blu-ray because of netflix.

A netflix subscription and a blu-ray player is both cheaper and more interesting than subscribing to all the premium movie channels.

[pyre]

Netflix is also on the XBox360. But that might not be relevant to you (not a gamer,bluray player cheaper,etc).