This was the extra pick the Eagles got for trading down with the Vikings, and they used it very wisely in my opinion.
Quintin Demps is a free safety from UTEP who has a great understanding of the game. He is not the fastest guy, but he is very smart, and is able to cover his ground well.
This pick fills a huge need, because Brian Dawkins can not play football forever. Demps has a year or two to develop behind Dawkins, and then hopefully he will be ready to take over then.