Even with "hardcore mode", I doubt BF3 will live up to PR/FH community's expectations. What people seem to expect is "PR lite". What they will (most likely) get is pimped-out vanilla BF2. I doubt that even the "hardcore mode" would have different ammo types for tanks, penetration/damage dependent on angle, etc.
That said, the editor's column in the local gaming magazine, speculating on the basis of recently announced titles, such as the second Halo trilogy, that sci-fi shooters would be the next pandemonium in the gaming industry, made me think whether the next BF title after BF3 would actually be a follow-up to BF2142 (along with the next CoD being "Future Warfare"). Which would mean that FH2 would remain the premier WW2 shooter for several years, since no new commercial WW2 shooter would be there to replace it due to big gaming companies focusing on sci-fi titles.