When WoTLK came out, it just ruined it for me. I loved TBC so much, mainly because back then I had my guild, all my guild mates and we were a pretty decent team and cleared most raids.
When WoTLK came out it just didn't feel like WoW at all. I got a couple of 80's and quit after clearing most of Uld and haven't bothered to go back.
I do miss the older times in WoW though, they were my best gaming times.
Had the same feeling to be honest. I really loved the instance structure in TBC and heroics actually being quite hard and quite unforgiving to mistakes. I use to farm heroics with a group of none guildies who i got to know really well and we all got use to each others playstyle so we could farm heroics for a few hours on a night to get some nice items. I also did abit of "hardcore" raiding and saw all of the content and thought for the most part, it was really good and quite epic when it came to fights like kael in TK.
Wotlk just lacked a certain charm when it came out. Whilst I liked the choice of which bit to start in, most of the quests where complete rubbish. I had 5 level 80s before I quit the game and 4 of them had uldaur or above gear level, basically from desperation to try and get the good feeling of playing it back. Won't be going back to it in cata or any of the patches though.
Left the game at the end of august