I'm a long *nix user, anda just upgraded to oneiric and found this HUGE button in the dash. I use a netbook and I don't have much vertical space, for me the other position was way better. So, I was wondering, how can I revert the dash button to the top bar?
That is not possible.
Even the new button is bigger, you save vertical space because other Places buttons (Applications and Files) of Natty are now integrated in the main Dash.
One bigger button more, two buttons less.