I think some people will probably be disapointed by Gingerbread look as it does not differs so many from Froyo.I've been really looking forward to it ever since the leaked blurry shots ha ha, and now that I've had a good look through the user manual it looks killer, there's a dump over on the N1 forums I think.
However, I like the new black theme, and especially the look of the keyboard (I know it's stupid to say that, but anyway I like its look). Also I feel the icons are more smooth. Still hard to say as the few pictures we have are not giving us enough to apreciate / judge the new look of it.
For now and for me, I will be glad to see the changes, and will be happy to test it when time comes.
Also, the Oxygen standard theme does quite looks close to Gingerbread I think. But that was pointed out by Adam somewhere in the Oxygen thread if I good remember.
Sarcasticly, I would like to see people opinion once they come to the point of realising that the stock Android theme does now looks as the Oxygen theme...