I wouldn't ever want them to do away with the current system, but adding an additional option could be interesting. I'm one of the few who actually wanted a first person camera view, but I also would never make that the only view.
I also juggle a lot of Sims and tend to create large households, so I think it would be harder to navigate in the WSAD or arrow modes that way. I think many people multitask the Sim commands by clicking here, clicking there and then there, to build a string of tasks or movement, to make things faster and easier. It also helps more with time management. Of course, Sims don't always perform the way we direct, but that's another discussion. :s
