I really do WANT to use Chrome, but there are so many Firefox extensions I just can't do without. One step closer though.
Not that I mind Firefox, but Chrome gets to do a reboot and start again without carrying legacy support/etc with it.
Early versions of Firefox felt "lighter" than IE to me for that reason.
It's probably only got more "lightweight" with time as they've had more opportunity and funding to optimise and actually remove things they don't use.