I finished Storm Peaks and Icecrown over the weekend. Both were very good zones. In particular, the first set of quests with the Argent Crusade was great. For the first time, the world changed with you as you accomplished goals.
I was stuck at 139/140 quests for Icecrown for the longest time. I could not find any other quests, and normally Blizzard gives you a little leeway in the quest count for the achievement. Finally after looking up the quests on Wowhead, I found I had missed one questline that started from a drop. I had just never killed that mob type before.
There are two things that disappointed in Icecrown. First, it doesn't come to an end. It's like the first book in a trilogy. All the other zones told a full story. I guess we'll have to wait for a later patch to finish the story. Second, Blizzard stopped doing voiceovers for the Lich King quest cutscenes. I think the Lich King voiceovers really added something to those scenes when they occurred in previous zones, and hopefully they put them in at some point.
I do have to give Blizzard credit for putting the Arthas front and center for this expansion, and really integrating him with the questing. It's a very refreshing change from trend of major storylines which only occur in raids.
So questing is pretty much done for me, and now I have to turn my attention to the other parts of the game. I still haven't decided what to do yet.
Also, where are all the breadcrumb quests that lead into the high end dungeons and raids? Isn't there a quest which sends you to Naxx? It might be deliberate, to allow non-raiders a true sense of completion, rather than having quests in the log which they will never be able to do. If this is the case, I'm not really sure how I feel about that. I can see the advantages, but it also seems wrong somehow.
 Technically I have one quest left in Icecrown. But on Skywall it's been bugged for the last few days. Hopefully it will get fixed during the server reset.