It is tentatively called the Boeing 797. We'll know for sure at the Paris Air Show. Agreed that SWA/ATN will probably be the launch customer.
I highly doubt that the 717's will be only in smaller markets. They will probably be put on "market segments" that support the number of seats. For example MSP-MCO may have 5 R/T's a day. On 3 of those flights, demand may be high, so you put a 737, or even a 737-800 on those. On 2 of those flights the demand may be a little less, so you put a 717.
Not trying to be a smart azz, but SWA will be the launch customer.LOL! I think the 717 will be in the majority of smaller markets. You boy's and girls just wait till SWA gets a hold of AT's aircraft.