I've never been a huge Fett fan, but I'm excited about the white-armor version--I'll either call him a new clone commander and put him in charge of some clonetrooper grunts, or call him a Mandalorian general and give him some battle droids to order around.
As for the concept stormie, I'll make him an elite stormtrooper guard/commander and toss him in with my various Red Guards, SOTE Coruscant Guards, EU Imperial Sentinel, etc.
I love a lot of the concept art from both trilogies, so I'd love to see more figures and vehicles made.