If you have not seen the WoW: Wrath of the Lich King site yet please do so now.
I can honestly say that this expansion looks to be the best so far. The graphics seem to get a small boost, instance design of the first dungeon seems top notch, new story arcs, and two starting areas that are neutral to both faction, at least it seems so from their description.
The graphics on the flame effects are very realistic. I wonder what impact this will have on the majority of systems out there. I am running a Pentium D 3.4GHz, 2GB RAM, 8800GTS SLI right. I still get lag in heavy pop areas. That lag more than likely has to do server lag but is still frustrating when running a higher end system. The flame effects could easily choke up others especially when 90% of your server pop is there doing the same quests. Ugh.
The instance design of the first dungeon, Utgarde Keep, is above anything I have seen so far in BC. Which isn't saying much as I have only been in TK a few times and some of the 5 mans. Yes that is a big content gap but I have my reasons. I love the fact that the story arc is works so seemlessly with the Keep. Just like a good fantasy book starts the reader off at the start of his adventure getting small hooks here and there. Eventually finding his way to the big bad castle with the BBEG (big bad end guy). I hope they can keep the story going so the other zones/instances are included. Not a quest that says, "Hey you just killed this big bad mofo that we couldn't touch. Thanks! Please go to this new area and kill 10 bunnies for Farmer Smith for 20s."
Having two starting areas seems like a good idea. From what I have read it will be something like Aldor/Scryer without the faction penalty. Get done with one and head over to the otherside to do all the quests, etc. Hmm nice.