Eric M Esquivel is an occasional writer for Bleeding Cool, though I get the feeling he's about to become a lot less regular.
He's taking over Freelancers, the new comic from Boom!, and just like Batgirl, he's being retrosolicited onto the title. He's scripting issue 2 and then fully writing the series from issue 3 on.
As to previous writer Ian Brill? No idea.
I hope he didn't get fired by e-mail.