It would be strange if they were switching to keeping the trainshed intact as part of the development. In the other concepts that have floated since the circus school became lead tenant, they were saving the two large brick buildings (A and part of C1 in the plan above). My hunch is that they would make C1 an enlargement of the existing structure (which is the one with the prominent "Mister Sparky" signage on top, easily the signature existing building on the Point). One thought that came to me was that, if they don't have a tenant ready to make building new on the trainshed site immediately prudent, they could clean up the shed and remove the east side to make a covering over the stage and premium seating for the concert area.
I'm glad to see the pier for water access. With some of the discussion that has taken place regarding a LRV system to connect the Point to downtown, I think we should use the already-in-place natural infrastructure we have: Duck Boat water taxis that could go directly from the PTC off the end of the Point (even at low tide), come back on land via the current Portland Yacht Services ramp, make stops (with permanent access ramps or lifts available) at Ocean Gateway, Casco Bay Lines, and the DiMillo's parking lot at Long Wharf, then turn around and come back to PTC the same way.
It's also interesting that the SoPo project is being driven by their new Assistant City manager, Jon Jennings, who was heading this project at the time that the concert facility was still part of it. My hunch is that this one won't host much more than student performances.
A side question: how many posts do I have to have made before I can post attachments? I have some photos I took of the Cross Insurance Center when I happened to be in Bangor during their grand opening Open House.