BC items include Feral gear

[Lissa]

It's my understanding that old items won't be changed with the exception of some of the hunter sets because of the big ways in which hunters DPS are being changed (1 agi = 1 RAP instead of 2, 1% crit = 33 agi instead of 52). So what I've read (and since I don't have a source take it for what you will) is that hunter sets will be the only sets revisited because hunters are getting bigger changes than other classes and it would break current itemization pretty badly.

I think they are intentionally not changing other items precisely to make it obsolete that much faster so that people get on an even footing faster. There's a portion of the population they've gotten hooked on the end game raiding now that is anywhere from slightly behind to way behind the gearing curve of some of the older raiding groups. Since even with 10 new levels of content and smaller sized raids, raiding is still going to be the end game of TBC if you can get more people in it together Blizzard wins. People who will be starting the game or picking it back up when the expansion comes out will be able to get back on even ground with the people that may be several major power steps above them. They want everyone back on the same playing field quickly. Making the new items that much better than the old stuff does that.

GG is correct. Outside of changes to Hunter items, there will be no change in pre-tBC items. How they are now is how they'll stay come tBC.