It could be....
I mean, part of me hopes it is. Planescape is fuggin' awesome, after all.
But another part of me kinda wonders....
If S&S *is* buying PS, I'd think that Wizards would have let those working on the official 3e version know. I mean, they probably don't have to, but I don't see why they wouldn't. It's good news all around. They'd probably want to make sure Branno and Ken and everone (or is that eveyrone?) could tell the rest of the PS3e Community, and get the word out.
If it's still in discussion, it may not be revealed to us yet, but it probably will be at some point.
Basically, S&S has a good record for this...I mean, they took Ravenloft, used what the online community generated, and gave it some new life. They could, in theory, take another much-loved setting (even something like Dark Sun or Birthright, but PS seems to have a bit more clout than at least the latter) and do the same.
Of all the settings they could take, PS seems to be the most unlikely. All the intellectual property invested in it -- mostly in the form of the Greath Wheel, the WotC gods, the Lady of Pain, etc. is fairly deeply intertwined with Wizards, and after the Manual of the Planes came out, it just got it's own form of 3e mutation.
Not that I'm saying it's not happening. I'm not sure even Brannon would know if it's happening or not, though he seems to have quite a peachy relationship with the Wizard people. I'll ask him about it in communication with him, and hopefully we'll get something.
