SE, I've tried to find where the 2nd mosque you refer to is located but without success.
I think, from what I've been able to find, there is only one mosque there and it's the one that has tried to expand but it is not they who are trying to build the second site and as noted on their site, they are not affiliated in any way with the proposed building of that Islamic Cultural center. Have a good read of the link I posted on the mosque that's been there for 40 years.
Edited:
Okay, I see where you are coming from but a slight correction. The 2nd mosque is located some 12 blocks away, not within 4 blocks. The other would seem to be from a breakaway Imam (
http://en.wikipedia.org/wiki/Feisal_Abdul_Rauf )from the mosque located further away. It is this Imam that wants to build the cultural centre (he currently conduction prayer meetings in the old Burlington Coat factory which IS inside the 4 block radius but this is apparently only spillover crowds from the younger mosque 12 blocks away. Apparently there is considerable difference in the way they conduct their operations as well. I, as well as the majority of Americans on both sides of the political fence, still think it's a bad idea. Not the building of a new mosque, but the proposed location.