Well, see, I was never a big fan of the switch to the street racing scene, but I never really thought the series went downhill, either. Sure, they abandoned the 200+, multi-million dollar game of tag that the series was known for, but I genuinely enjoyed the racing in the later games like Underground 2 and Carbon, and I loved the ability to customize your car. The games grew on me. That said, I'm super excited for Hot Pursuit to be back.
I hope they include a story mode. I don't hope they include a story, or at the very least I hope they lave out the cutscenes. I just beat Carbon, and by then I was tired of having my game interrupted to watch people wearing too much eyeliner try to exposite a poor story that the writers themselves didn't seem to know what to do with.
On reflection, some sort of story would be nice though, if only to keep you playing forward.