There are a few decent low draining live wallpapers out there. Days of Ubuntu and WP Clock come to mind. According to Better Battery Stats, they're barely a blip on battery drain.
For those of us who want to game or watch videos full screen but don't want to give up the stability of stock, it's worth the tradeoff. Or at least it's as good as it gets. I'm unaware of any other solution (GMD is a pain in the arse).
Sent from behind the wheel of my car at 95 mph.