This interview with Niqui Merret and Aral Balkan makes good reading for those trying to work out the general situation regarding Flash and accessibility.
I’ll be keeping an eye on Niqui’s site in future too, as it looks like being a good resource for anyone looking at accessibility in general.
Over at OSFlash they’ve released a tool which aids in the detection of a screen reader (before throwing them tons of AJAX or incompatible Flash). After a quick squint at the code it seems they’ve accounted for Flash not returning correct values for screen reader presence until a few seconds have elapsed, so it looks like good stuff.
Check it out here.