Yo. One of my friends was accepted first-round via e-mail by Berkeley, Stanford, Chicago, Princeton, and Harvard. Harvard's notice came around Feb. 6th to 9th, all of the other ones were between Jan. 28 and Feb. 2nd. I also heard through the grapevine that MIT and Columbia have sent out their first-round acceptances.
Finally, another friend of mine on the west coast got a paper rejection letter from Harvard on Thursday, Feb. 12.
I was accepted by Berkeley on Jan. 28th via e-mail. Stanford sent an e-mail to me on Feb. 12th saying that they would have all decisions finalized and all applicants notified of their status via e-mail by Feb. 28th. Other than that, as of the time of writing I have heard absolutely nothing from any of the programs I applied to.
Hope this helps.