If you haven't hit the redesigned Azshara yet, you totally should. Heehee rockets!
The only problems I've run into are....
1. The doorway is an illusion bug. This has happened to me in the Stockades room (I couldn't go through the doorway, there was an invisible wall), and to a guildie in Gundrak. Very annoying, but easily fixed.
2. You move, you dc. Happened in Howling Fjord, and had something to do with the water in the bay. Hearthing worked like a charm to get out of it.
3. The portals are gone. Yes, I know this was intentional on Blizz's part, but I miss them! Could the Alliance get a portal to Tanaris in Darnassus or something? Having two cities up in the north of the continent makes flying to the south a pita. Or maybe they could give the Horde a portal to Tanaris in Orginmmar and a portal to Booty Bay in Undercity, and the Alliance gets a portal to Tanaris in Darnassus and a portal to Booty Bay in SW. That way there's still no portal hub per say, but the time spent flying factor is greatly decreased. Especially since we'll be spending time in Uldum, and man that flying's going to be a massive pita.
Honestly, I'm having way more fun on my lowbies now. I'm hopeful that when Cat hits, Lyllea will again be the center of my attention, but until then she's mostly neglected. I did go work on Glory of the Hero with her (and some of my wonderful guildies and it was a BLAST), and I have all the Occulus achieves but Amber Void now. Still have 14 or so to go, but I'm not in a hurry. It's really just something to do.