Return the TV.
Shop around for the Panasonic 50" in the 77U series (which has the anti-reflective coating) or look at a site like New Egg and go for last years Pioneer PDP-5070.
1080p will only be a factor if you are sitting 6 1/2 feet or closer. But for a 50", you're ideal distance is about 8 or 9 feet... and at that distance you can't visually resolve much of a difference - if any - at all.
Look. You can't future proof - you know new technologies and new resolutions are right around the corner. I have two 768p displays and the pictures are absolutely fantanstic - both are only several months old. Don't fall into the trap of thinking that 1080p is a total necessity. Either the panasonic or the Pioneer listed above have the ability to accept a 1080p signal and downconvert it to 720p/1080i... and any HD player you buy can output different resolutions. Besides, most channels only broadcast in 720p (some in 1080i)... but bandwith is such an issue right now that 1080p is not broadcast.
If you really want to convince yourself that 720p (or, 768p) is okay to purchase read the industry expert comments by the www.hdtvexpert.com
. He's an industry consultant/expert.