LAX-DEN flight last night on an E175 had wifi. Plane still had that new plane smell, and the FA in first was a lovely Japanese woman...she even knelt down to take our drink orders as they do on JAL. According to her, all the Compass E175s are new and have wifi, and they supposedly will be placed primarily on LAX routes. So it seems a pretty decent chance that routes out of LAX on E175s will have wifi.
On a slightly different note, I thought there would be some sort of a meal on my dinner time flight (when I booked on aa.com they had 'Dinner' listed under meals) but got only nuts. Not even the snack basket that they had post 9/1.