842 is having success in that area:
http://www.youtube.com/watch?v=EUEg4...-7qMxw&index=9
We're also planning on a floor pickup using the same concept (lexan flap + roller intake). I'm not seeing successful floor pickups on more than 50-60% of robots this year, mostly due to a lack of interest in attempting it since the feeder slot is so convenient and the game pieces are so awkward. But I've been wrong before!
Another interesting question might be how many teams are attempting to pick up inverted discs and of those teams, which will fire them upside-down and which will include a mechanism to right them.