As I was posting shortly after September 11, there are lots of different flavors of Islam. It's actually playing into the hands of the Ladenites to assume that Wahhabi extremism represents the authentic face of Islam. Islam has many traditions, and Wahhabism is actually a fairly recent one, and it is rather more extreme than it is authentic.
That said, it would be useful if those more moderate Muslims would take a more aggressive role. Some are -- see, for example, the Free Muslim Coalition Against Terrorism -- but we could use more of that, no doubt. But to the extent that these people encounter comments urging that Islam be "banned," they're likely to feel less, rather than more, motivated toward reasonableness.