no, it's a chip that takes the incoming 16 PCI-E lanes and then gives each GPU 16 lanes. Supposedly, it also intercepts GPU-GPU PCI-E communication so it doesn't have to go through the chipset, too. Yes, there's also an additional SLI bridge, too, but it's just a link and not run by a separate chip.
The original 7900GT*2 (whatever its name was, the OEM special with the GPUs on one board, not the 7950GX2) didn't have this chip. It just gave each GPU 8 lanes, but also had to be recognized as 2 PCI-E devices, hence the need for a very special BIOS in order to get it to work).
The original NF100 was a bridge of this type that was on the 7950GX2. I think they updated it to the NF200 for the 9800GX2, and also used it on the 780i . The Skulltrail used 2 NF100 bridge chips. If the 9800GX2 and the GTX 295 do not use the NF200 it is a chip of similar functionality, at least. It may not have a name, but I'd guess even if is not divulged to be the NF200, that's probably what it is.