He's said he'd do something like this before and then not followed through. So keep that in mind when you hear that:
"Ali Abdullah Saleh, the president of Yemen, has arrived in Saudi Arabia to sign a Gulf power-transfer initiative brokered by the six-member Gulf Co-operation Council (GCC), the country's state television has reported." (Al-Jazeera)
Yemen's Foreign Press office has released this statement:
"Earlier today, the Honorable Ali Abdullah Saleh, President of the Republic of Yemen, arrived to the capital of the Kingdom of Saudi Arabia (Riyadh) to participate in the signing ceremony of the power transfer initiative brokered by the Gulf Corporation Council (GCC). The transfer of executive powers to Vice President Abdo Rabu Mansour Hadi will be effective immediately after signing the accord. Furthermore, a high level delegation representing the opposition coalition is en route to Riyadh to sign the practical mechanism and timeline accord for the GCC initiative brokered by the United Nations. This monumental agreement will hopefully bring an end to the ten-month long turmoil in the homeland."
As The Associated Press says, "Saleh's signature on the Gulf-brokered accord — if he goes through with it — would start a new chapter in the ... popular uprising that has shaken the Arab world's poorest country. Since January, tens of thousands of Yemenis have protested in cities and towns across the nation, calling for democracy and the fall of Saleh's regime."
The BBC reports that "the deal, Mr Saleh would step down and hand over power to his deputy Abdrabuh Mansur Hadi in return for immunity from prosecution. Mr Hadi is then expected to form a national unity government and also call for early presidential elections. Some reports say that Mr Saleh will remain an honorary president for 90 days after the power handover."
There have been hundreds of people killed and thousands wounded in Yemen as Saleh's government cracked down on dissent.