I think he probably will, mainly because there's no-one else who's really up to the job, or who would have support across the whole of the parliamentary party.
Truss is a loose cannon, Sunak's now tainted because of the non-dom business, Javid also exploited non-dom rules, Hunt was pro-Remain and won't have the support of the ERG headbangers, Tugendhat has no ministerial experience, Wallace's experience has been very limited, Gove is too weird.
The only 2 names that I've heard mentioned that don't have things about them that would make them palatable to a large section of Tory MPs are Zahawi and Mordaunt, and Mordaunt again has very little experience. And I can't see Zahawi getting broad support, either.
Interesting times though. I wonder what time they'll be voting? Although I don't think Johnson will lose, I'd stay up on the offchance that he does, simply to see his reaction.