Bachmann absolutely will endores Romney—100% sure.
But, she’ll wait until after Mitt get’s bloodied in the NH & SC primaries, and starts to get a little desperate. At that point she can TRADE her endorsement for say...the VP slot on the ticket.
There’s a reason Bachmann NEVER went after Romney in the debates (heck, she even bailed him out big time in the LV debate). She knows her path to bigger things is on the VP slot, then onwards and upwards.