This video may be a little outdated as it came out before the two game play videos, but its still worth a watch. It brings up some interesting points.
Kudos to the guys at GamerSpawn
Heres some Facts comparing Bad Company 2 to BF3
BC2 - 19 Vehicles
BF3 - 48 Vehicles
BC2 - 4 Classes (Assualt, Medic, Engineer, Sniper)
BF3 - 5 Classes (Assualt, Medic, Engineer, Sniper, Support?) Unconfirmed
BC2 - 48 Weapons
BF3 - 34 Weapons?
Of course all of these stats are and will be totally unconfirmed until BF3 is released