Well like with any green screen 99% of the job is lighting, nail that and even DV can be easily keyed with a competent effects artist. but if you're asking is there anything particular about the EX3 that would inhibit green screen shooting, not that I'm aware of.
EX3 is very "Key Friendly".
Enhanced dynamic range and 1/2" chips
makes for a very nice, easy to key image
compared to other pro-sumer cams.
The edges are less pixelated than our
Canon H1, which is still a great camera for