Since im in charge of Hoth , I better answer some questions about it 
It will be very much a push map , as you may expect...however there may be a little twist to it.
The main priority for the imps will be to get to the SG , blow it up , then enter echo base .
What the objectives inside Echo Base arnt fully finalised but it may include destroying certain consoles or something of that nature.
A timer may be introduced ...whether that be an actual clock or the Imp's ticket count bleeding.
A side objective will most probably be to destroy the Ion Cannon to allow for a time/ticket bonus (reinforcements) . This would be to simulate the Imperials being able to land more troopers etc due to the lack of orbital defence from the rebs.
As for ATAT's being Titans .. its unlikey
1. Would the Imps stop fighting if the ATAT's were destroyed?
2. If they are done like bf2142 titans ..then we dont know if titans can only be moved via point and click. It may be hardcoded .
ANother bit of info is that this map will most likely be the most movie authentic Hoth map you will have ever played. Mountain structure , Trench positions ..sizes and shape , weapons used , equipment , echo base will all be as close to the movie as humanly possible.
I made a 'Monster Hoth pic' for Blitz where it shows the layout and then has pics from the movie dotted all around it with arrows pointing to the correct places on the layout. We are aiming to be able to match up screenshots from our map to be exactly like the screenshots in the 'Monster pic' .
Hope that helps some..
"Government is the great fiction, through which everybody endeavours to live at the expense of everybody else."
Frédéric Bastiat