Yes, if anyone can push Gamecube's hardware, it's Factor 5. And, seeing what Silicon Knights has been able to do, let's hope they announce something soon--because I'm getting thirsty!
F5 has had an immense amount of time to make it, seeing as they had finished Rogue Leader before Gamecube's Launch. And, it'll probably make great use out of their new Gamecube DivX... Mmm...