“Tentative” is the key word. From CNN:

North Korea has tentatively agreed to close down its nuclear weapons program in exchange for energy aid, U.S. and Chinese officials said Tuesday. But the proposed deal was being reviewed by officials in the negotiators’ capitals before becoming final.

[. . .]

Hill said the talks would resume at 10:30 a.m. Tuesday (9:30 p.m. Monday ET). (emphasis added)

The New York Times:

In essence, the draft appeared intended to prevent the North from producing more weapons, but to defer discussions over the weapons and fuel it has already stockpiled. Mr. Hill had earlier suggested that if the current talks were to yield an agreement, follow-up discussions could be held in March and April.

The summary calls for the six nations in the talks to “create working groups for full and rapid implementation” of a September 2005 agreement in which the North agreed in principle to abandon its nuclear weapons. (emphasis added)

And the Washington Post:

The draft agreement, worked out at the latest round of six-nation talks on the North’s nuclear program, contained commitments on disarmament and energy assistance along with “initial actions” to be taken by certain deadlines. . .

A few observations. First, Japan has stated that it will not fund any deal with North Korea until the abduction issue is concluded. Second, this deal calls for “working groups for full and rapid implementation” of the 19 September 2005 Joint Statement (DOC), that North Korea dismissed the next day (DOC), and which calls into question the not-even-done-deal’s life expectancy . Third, this agreement only freezes activity at the Yongbyon reactor and does not address stores of weapons grade plutonium or nuclear weapons. Fourth, it does not seem to address the uranium nuclear program, which would then be included in the, “working groups.”

There are multiple points of failure in this “tentative” agreement. History shows that North Korea will use any real or perceived reason to renege on agreements, drag out negotiations, etc., and then blame the failure of diplomacy on the U.S. or other parties. I won’t be surprised if North Korea quickly ends this deal, or drags it out for weeks or months, and stand by this disclaimer.

Also see OFK.

Update: also see; the Marmot, ROK Drop, and the Nomad.