Well, this ought to be the clincher.
IGN has reported feeling something strange when playing Burnout Paradise at EA's pre-TGS press event: the Sixaxis controller, which we all know well by now, shook. That's right, it when a rumblin' in their hands, which can only mean one thing, and we shouldn't have to spell it out for you. But one interesting side note: considering they didn't notice when they first put their hands on it, the new rumbling Sixaxis will apparently look exactly the same (besides a sticker they saw that said "Rumble," and a significantly heavier feel).
Evidently, the rumble felt similar to the PS2 Dual Shock's rumble, and as of now, we're just waiting for the official confirmation at Sony's press conference tomorrow. Well, it'll no longer be any kind of surprise when the announcement comes, that's for sure. Rumble on, Sixaxis!