The old address for Friends of Weiner was also changed from 1 ASCAN AVENUE #31 FOREST HILLS, NY 11375, as the 2007 Statement of Organization indicated, to 254 PARK AVE SOUTH SUITE 12A NEW YORK, NY 10010.
Since Weiner still has close to $5,000,000 in his war chest, and has until June to decide if he wants to run for NYC mayor, this might just be some sort of temporary stop-gap. It seems extremely unlikely that Weiner would fight for his old seat, just a year after the Weinergate scandal.
According to Melissadata, a filing appears to indicate that the "Candidate is the challenger in the current election cycle" for NY-9 in 2012.
I've contacted Friends of Weiner and will update this post if I receive a response.