Yes!
Although I'll be learning Archaeology and old world flying on my DK then going off to play with that for a while. Screw new zones and new start zones on opening night! (I remember HFP on TBC opening night, was hellishly <pun> busy.)
Blizz eased that somewhat with the release of WotLK by having the two starting areas. I went out early in the morning on WotLK release day, so was online by about 9:00am. I didn't notice too many folk about, and it certainly didn't feel overcrowded. Of course, more folk will be only at launch, but again, there's two 80+ levelling zones to choose from, and also the RDF, which wasn't around with WotLK launch (I think).
Also, quite a few will be funnelled into the Worgen/Goblin starting zones (probably myself included).
Hopefully, it will be nowhere near as bad as TBC (which was horrific
).