Yeah I think you're right considering how large games are these days. I have two 500gb EVO's and they're filling up fast.
I don't tend to keep many games loaded on my system if I'm not playing them. GTA4, finished it, why keep it on? it's gone, Diablo 3, maybe I'll get back in the groove and reinstall it at a later date, I have a 180Mbps line so I'm not really worried about download, FarCry 4, that's gone, I love it but there's only so much I can replay the missions. Of course most of this has been a matter of necessity as the largest HD I've had has been 250GB.