Ok, I get it now.  This is my first pair of yoga pants.  I understand why they are so popular now.  I don't do yoga so I never considered that I should need a pair.  But, these are great!  They're comfy like sweatpants but they make me look great and not like a huge slob.  I wouldn't wear them to dinner or anything but I do feel more "dressed" than I do in regular sweatpants.  I found they were pretty true to size and they seem well constructed.  I'd buy another pair.
Update 1-25-13: I bought another pair in brown.  They seem to be pilling slightly inside the legs and I haven't been wearing them very long.  It's not very noticable but you can feel it.  The black pair has not started pilling yet.