Maybe it is just me expecting to actually see something different but each version change for a while looks the same as the one it just updated. I imagine there is more going on under the bonnet, so to speak, but the UI appears the same. I noticed no difference in speed etc from version 8 than when I was on 7.01 or when I have tried the nightlies.
Then again I have just noticed that my Dev version of Chrome has just changed from 16 to 17 and that too still seems the same.
Still I do prefer to use FF even if it is just for the great extensions I use that Chrome does not yet seem to enjoy.