Looks like Newt has set a date. NBC News reports:
Per @AlexNBCNews, NBC News confirms that Newt Gingrich will suspend his presidential campaign on Tuesday, May 1st in Washington, DC.
— NBC News (@NBCNews) April 25, 2012
Source confirms Gingrich will suspend his presidential campaign on Tues. in Washington,DC; “high likelihood” he’ll endorse GOP nominee then
— Alex Moe (@AlexNBCNews) April 25, 2012