I've no doubt we'll be seeing some tweaked weapons as well as new ones in JKO. They haven't mentioned Rail Detonators and Concussion rifles yet. Personally I wouldn't miss those weapons too much, because I didn't use them that much. I'd like to see a few inventive alien weapons to use - perhaps some things that haven't been seen before.
As for sabers, well, there are a lot of topics started already discussing that issue.