What if Flash Were an Open Standard?
That’d be an interesting move, and it would certainly shake things up. But what if the source code to Flash Player is — as many would wager — a huge steaming pile of convoluted C++ horseshit? It’s sort of like what if Microsoft open-sourced the Internet Explorer rendering engine. It’s not like anyone who is now using WebKit or Gecko would switch to that just because it was opened — or that WebKit, Mozilla, and Opera would suddenly be obligated to or even interested in adopting IE-specific web features.
The problem for Flash is just like the problem for IE — the web has already moved on.
I don't think that opensourcing Flash can be a silver bullet for Adobe, but I'm pretty sure that the project would get a traction in the community. Flash still offers a lot of functionality that is otherwise unavailable for lots of users, e.g. for people stuck with IE.