Prime Minister Netanyahu's move comes extremely late in the game. The call for negotiations is not 11th hour but it is pretty close. It is also an escalation from the Prime Minister's signaling late last week that he would be open to raising the level of Palestinian representation at the UN. The move towards negotiations now is likely the result of pressure from two sides. On the one hand, Prime Minister Netanyahu is likely under pressure from the United States to present the Palestinians with an alternative that can be a basis for negotiations at best, and undermine the bid's legitimacy at worst. On the other hand, Netanyahu faces domestic criticism including today's comments by opposition leader Tzipi Livni that he is damaging the US-Israel relationship in being intransigent towards the Palestinians.
Signaling a desire to come to the table, however, is an excellent political move by Prime Minister Netanyahu. Floating a willingness to negotiate in the days leading up to the bid will shield him from domestic criticism that he was intransigent. Furthermore, as with his handling of the settlement issue, Netanyahu's call will align with the United States soon enough that he can't be accused of antagonism, but late enough that the move is drained of most of its political salience. The latter component will be critical for Netanyahu's standing with his far-right coalition. Finally, the call for negotiations is consistent with Prime Minister Netanyahu's stated policies up to this point (though in practice it may be another story).
The two key questions now are whether PM Abbas sees the call for negotiations as in his interest, and if so, whether he can sit down to negotiations while saving face. Some analysts argue that Abbas intended the statehood bid as a mechanism to push Israel into negotiations in the first place. Furthermore, entering negotiations has payoffs for Abbas in terms of real gains on the ground. However, given the critical stage of the bid and the immense pressure he would be under to produce tangible results, Abbas may very well let the statehood bid go forward, calculating that he could sit down for negotiations after the statehood bid as well as beforehand.