If omegle was released in the next months, it likely wouldn't use flash.
http://www.bourkedesign.com/wp-content/uploads/2010/10/ie-po...
While many people appreciate the benefit of better browsers there is still a significant portion that don't and hopping aboard this wagon prior to full adoption means that you exclude them or present roadblocks to them.
I have the added benefit of targeting (in part) the older generation with the software I produce making all this excitement muted without cross-browser consensus.
Does flash come pre-installed in Windows now? The last windows I used was XP, and it didn't come pre-installed in XP.
If it we me and the choice was between supporting older browsers or supporting mobile, mobile would win out.
also, the sort of enterprise you speak of would certainly not be purchasing software like these - they'd stick with the trusted and known big name vendors. As they say, nobody ever got fired for using IBM (or microsoft).
If you've got a contact who trusts you then you could certainly pitch solutions to them, and the prices you can charge are a lot higher.
Do you want to work in an environment where your target browser is IE6 though (not even joking).
I'd still try to go with js/html and shim away as best I could for older IEs.
and yes, I'm putting it bluntly ;)
Meanwhile, voice and video enable [your app] for the other 70% of your users.
Can argue that WebRTC is not really about universal calling regardless...and yet still a game-changer:
[0] http://arstechnica.com/information-technology/2013/01/micros...
[1] http://blogs.msdn.com/b/interoperability/archive/2013/01/17/...