I ran into this when I made my worgen. The starting area was simply amazing. I was briefly confused because I didn't realize there was a significant bit of time between the two parts, but beside that, the zone just blew me away. I felt like I was in a city under siege. Which of course I was, but that is something that WoW often fails to convey. So all in all a great time. And then I hit whatever level, finished a last quest, and got dumped in the nelf area. Hm.
As I've said before, the nelf area is a lot better now, but I've done it before and even improved it's a major step down from the worgen.
Suddenly my worgen might as well have been a nelf. Not cool.
It's probably asking too much that different races have different play experiences. I mean, even different classes all do their questing pretty much the same way. Maybe it's not impossible, except to balance, and therein lies the problem. Everything takes a back seat to balance, or at least the illusion of balance.
I wonder if vampires could make any sense...