Gigawire is supposed to be a Firewire 2, which Rendezvous is very much something different. It is reasonable to assume that "Gigawire" actually Firewire 2 because A: We know a firewire 2 is coming (Firewire is behind USB2 right now, and we cant be having that), and B: the fact that they share "wire" in their name.
Furthermore, If Gigawire were Rendezvous we would have heard by now, probably.