Actually, DL apparently is maxed out on 71-76 seater capacity, but has some 51-70 seat flexibility left before they reach that limit.

So they can't be over 70 seats. The only option before the first class modification will be 70 seat all coach at 34" pitch.

The decision was made to go to 9 First Class seats on all E170 aircraft, even the new Shuttle America E170s that are currently flying in 6 First Class configurations. This will be completed on Compass and Shuttle America aircraft by the end of the year, but none until after summer.

This is what I am hearing. Let's hope it is true. 9 First Class is obviously much better than 6 First Class.