From what I've heard I dislike the attunements.. the idea that you HAVE to go through the earlier raids to get to the newer raids. I wouldn't mind having the gear relatively close though, so while you don't HAVE to do the earlier raids you have a reason to do them nonetheless and you can still get upgrades, as opposed to being able to bypass them completely.
As it stands right now, in WOTLK, there is no reason to go to Naxx, Ulduar or (arguably) ToC for gear upgrades. Either you go solely to faceroll/zerg the content for achievements and JPs, or for mounts/titles (not quite a zerg/faceroll), or you don't go at all. There's no reason someone needs to go to Naxx, even as a fresh 80, for gear upgrades and, ironically, as a fresh 80 they're less likely to get into a Naxx run now than when Naxx was current (because everyone wants to faceroll/zerg Naxx). Same with Ulduar. There's no reason to even DO the content from a "Hey I could use an upgrade from this low-level heroic piece I've been using" standpoint, because you can do easier content and get better gear.
THAT is what I'm afraid of happening; it won't matter to me personally (at least on my main and primary alts) because I'm going to be there at Cata's launch but I know what I went through in Wrath; I tried to gear up from heroics (as in the drops, not badges) and then when I was looking for something to progress to I got told that nobody bothers with that junk, just run heroics for badges.