So slashdot, always bastion of reliable news reporting, had to bring the news: "Bell Labs Unix Group Disbanded", from this others went on to deduce that Plan 9 development has stopped.
Nothing further from the truth, not only is Plan 9 development at Bell Labs ongoing but development outside the Labs is as active as ever(and expect more news on this front soon).
1127 ceased to exist some time ago. The department was renamed and got a much longer number which, of course, I can no longer remember. The current split of what's left of 1127 is not considered to be a big deal by most members of the department. There have always been many interdepartmental collaborations, so 1127 has always been more of a management entity than a group/club/fraternity.
Plan 9 is alive and reasonably well as our current vehicle for wireless systems research. Plan 9 has gone embedded (but rest assured, all our wireless software runs in user space, using Plan 9's real-time scheduler to make sure it runs when it needs to.
Using Plan 9, wireless code becomes useful in a fraction of the time that code can be made to run on all those commercial embedded operating systems (which I do not care to mention) and also much quicker than on Linux which I am sorry to say is just too large and illegible.
May the research go on!
And don't let the "Fourth Edition" release date fool you, Plan 9 ISOs are built from the latest code every night, and the current codebase is very far from what Fourth Edition was, it's just that nobody has been bothered to make a new "official" release. Plan 9, as usual, is more about code and quality than about hype and buzzwords.