What streets did this happen, on, then, and why was this reported nowhere outside of he said/she said rumors, and random links to a debunked video that was actually in Palestine long before 9/11? Ask them the streets now, and I'll wait to see what you come up with. (Michigan? Ford Rd.? Greenfield? Warren? Outer Drive?)
Dearborn is at most 50% of Arab descent in areas, with Muslims being a little less, and the home of Ford, full of non Muslim workers who commute there constantly, including that day (of which I was one of them). The uproar of "Muslims dancing in the streets" there, on that day, would have been so terrible that it would have dominated news cycles constantly due to the eruption it would have caused. Those rumors popped up via word of mouth (or Internet) when it happened, and they were baseless. When they do celebrate, ie. when Osama was killed, there actually -are- reports, and video, and evidence: (http://www.wxyz.com/news/region/wayne-county/metro-detroiters-and-local-muslims-react-to-death-of-osama-bin-laden)
So, please point to some actual evidence of this happening, to enlighten someone who actually drove through the place on that day, and observed plenty of somber Muslims firsthand? Is this when "one of the largest Muslim communities was dancing in the streets" gets backpedaled down to "well this one neighbor of theirs was seen through their living room window dancing...so that's why there's no evidence..."
That's what happens when things are made up - you sometimes run into people that were actually there and know what they're talking about.