This is great news...they will be working on a platform for "creating next generation internet applications (codename Zorn)."
I'm a heavy Eclipse user now - not saying that I wouldn't continue to buy the Studio package as it evolves. but i like having a "coder-focused" tool in which to do my work.
Also. having Macromedia join with the other heavyweights throwing their support behind this platform can't be bad!
Mike Chambers has a little more on his blog too.