Apparently Alvaro Dias isn't going to endorse anyone, but I'd expect his voters to vote for Bolsonaro in the runoff of simply vote null/blank. It seems that Meirelles won't endorse anyone but just like Dias' voters, his voters will likely vote for Bolsonaro. Alckmin and other PSDB leaders will meet tomorrow to discuss who to endorse. Marina said she will be in the opposition regardless of who becomes president. Ciro is, obviously, going to support Haddad.
Some of Temer's allies who were defeated yesterday like Medonça Filho and Bruno Araujo are endorsing Bolsonaro.
Has Temer himself endorsed anyone? Probably it doesn't matter because he's polling pretty badly.