I have both a PS3 and a 360, and I honestly go through spurts with playing them both. I played my PS3 when I had MGS4 and TW09, and it's been a few months since I've played it. It'll gain usage once I get Assassin's Creed II and FF13.
But yeah, I understand what you mean, Freak. There isn't a WHOLE lot of PS3 Exclusive stuff at the moment that justifies owning it. And if you're only into sports games, then having a PS3 doesn't make much sense considering you are happy playing the original XBox.