The news could be sad to some, but it is also a sign of greatness for the potential of Battlefield 3. Karl Troedsson, GM of DICE has stepped forward to tell the eager community that Battlefield 1943 and Battlefield: Bad Company 2 Onslaught have been officially cancelled.
He mentions that there was a crossroads where a decision needed to be made - putting effort into those 2 (and now older) games or going full steam ahead and putting all concentration into Battlefield 3. I think the decision was a good one, as BF3 is using the next-gen Frostbite 2 engine which should really shine on PC given that it fully supports DX11.
Frostbite 1.5 (which powered Bad Company 2) looked hands-down amazing compared to the wizards sleeve that is Call of Duty... especially given that FB1.5 was only a DX9-based engine. FB2 should really push the boundaries and I think this is what DICE are going for.