1:38 p.m.: Is all this last-minute negotiating for nothing? Rep. Mike Rogers says that even if the Senate gets a deal done today, there's not enough time for the House to pass it, CBS News' Jill Jackson reports. "I just don't see it happening," Rogers said.

1:23 p.m.: The New York Times' John Harwood reports that a tentative deal has been reached. According to Harwood, it looks like this: Joe Biden and Mitch McConnell have agreed the Bush tax cuts will be extended on income under $400,000 for individuals and under $450,000 for couples (income above that will go back to the 90s rate of 39.6 percent.) The estate tax -- which will hit estates worth $1 million or more if we go over the cliff -- will be 40 percent on estates over $5 million. The capital gains tax rate will go to 20 percent.

Obama will speak to "middle class Americans" at 1:30 p.m. Watch here:

1:05 p.m.: Negotiators want to make sure the public thinks they're working hard. Politico's Jay Westcott tweets this photo of Senate Minority Leader Mitch McConnell meeting with senior staffers "behind closed doors."

1:00 p.m.: Ezra Klein has several new details on his Twitter feed about the mini-deal, including the big news that it would permanently patch the Alternative Minimum Tax rule, a fix that currently must be voted on every single year and would cost taxpayers millions if not amended.

12:53 p.m.: The markets seem happy with the current state of things, if that means anything to you.

12:47 p.m.: Progress? Calling the Democrats Senate bluff?

FLASH: Majority of Senate Republicans expected to support tentative "fiscal cliff" deal - senior Republican aide bit.ly/XpLNN3 — Reuters Top News (@Reuters) December 31, 2012

12:40 p.m.: President Obama is planning to deliver White House remarks about the cliff, "with middle class Americans" in attendance.

12:25 p.m.: New "sticking point": The delay on the sequester. As Chuck Todd and others reported earlier, the Democratic leaders were looking to delay the automatic spending cuts called for in fiscal cliff. The mini-deal calls for a three-month delay, but some key Democrats are insisting on a one-year delay to take the possibility of another showdown off the table for awhile, especially since there's already one coming on the debt ceiling.

12:06 p.m.: Ezra Kelin of The Washington Post insists that even though the President consistently caved on taxes, when the debt ceiling comes up again in two months he will absolutely not give on that. That time he will really mean it for serious!

11:39 a.m.: The deal may still happen, but looks like nobody, Democrat or Republican, is happy about it:

Well, the more folks on both sides in House and Sen learn about this McConnell- Biden deal, the more they don't like it.#facepalm — Chuck Todd (@chucktodd) December 31, 2012

11:28 a.m.: Slate's Matthew Yglesais argues that letting the fiscal cliff happen maybe wouldn't be the end of the world. (Short version: Ben Bernanke and the Federal Reserve have recently changed course and could step into avert a full recession.)