I still recall seeing the mail years ago, when the tools group told us that Teamware was EOL, and would not be supported any longer. I recall thinking, OMG, what are we going to do for ON? At the time, it looked (to me at least), like BitKeeper was a logical replacement.
Now here we are, years later, and with the closure of build 96 last night, we have finally stopped using Teamware for new development at Sun.
Mercurial/Cadmium seems like a powerful and capable replacement, and has the advantage of being open source. This is one of the most significant technical hurdles to fall that has kept external folks from being able to commit directly to Hg. (Opening up RTI, and the bug tracking database are the two remaining big ones. RTI can probably be opened without too much difficulty. The bug tracking problem is a different matter altogether.)
As a nice side effect, external folks can now have their changesets integrated directly, without requiring sponsors to do conversion work, and without requiring sponsors to place a "contributed by" credit. (Because the changeset will already have the contributor's e-mail.) This should significantly reduce the amount of effort required for sponsors, and consequently make it easier for more people to contribute.
Big thanks to the SCM team!