Is Stryker, I would assume still in low production, the answer? How about an up armored USMC LAV. Not nearly as big as the Stryker, but in the standard configurations has more firepower. I don't know their relative armor levels, but the LAV is small enough for city streets and the 25mm cannon is sweet.
Stryker is *an* answer for some things; probably the engineer version, maybe the medic version [though it only carries two litter patients- we've got a couple of FReeper medics who may have better viewpoints on that] and possible the new 105mm sp artillery piece. But at 3 million bucks apiece, it's an awfully expensive tripod for a .50 machinegun....
The LAV is a good answer for the Marines, but their vehicles are aging and replacements may be necessary down the road. I think it can be expected that their vehicles will probably need to retain an amphibious capability though, and that pretty well leaces the Stryker out.