The only qualm I have (and it's a small one) is their confusion of 'marketing' and 'promotion'. As the publisher, they should shoulder the marketing aspect and from the sound of their Tips page, they seem to try to do just that. I would change the term Cooperative Publishing because when I read that my immediate thought was they were going to ask for money. They don't, but it's an icky phrase. Saying something more along the lines of 'we expect the author to promote the title' would be better.
I don't see any warning signs. Best thing you could do is check the books on Amazon to see how their sales rank, and/or email them or their authors to ask about sales, etc.
Refreshingly literate website (as one might hope, given it's run by college professors), and they're up front with what they can and cannot offer authors. Could be a step above the usual hobby/amateur mircopress, but I'd like to be able to read excerpts to better judge their design and editing.