I'd like to point out that the 20v max name is just a marketing scheme, as the same exact drill in the UK is sold as 18v. That being said, these are still the best drills on the market today.
And to the derogatory nicad commenter, they might be heavier, but I've yet to see a Lion battery outlast one in charge cycles, and they don't hold a candle to nicads for extreme cold/hot performance. Best thing about the new Dewalt Lions is the availability of a whopping 4 amp/hr version.
NiCad is surprisingly useful in a drill
I was given a DeWalt 18v NiCad drill, and I've been amazed by it (I was a corded-only drill guy. It never made sense to me to buy a $80 cordless drill that could only do 25% of the work a $30 corded drill). The batteries keep a decent charge, even if I'm not using it for a few months (eliminates the old DIY cordless problem #1, no charge when you start a project)
But with a spare battery pack, I can fast charge 1 pack while I use another during some halfway significant projects, including drywall.