That is not the ending, that was a cliffhanger, it has but been officially comfirmed that the Jim Hansen company is making a 4 Part mini-series to tie up the major loose ends to Season 4 and make it more attractive for syndication.
You can read it here: http://www.watchfarscape.com/
Yeah right, and they will be making a movie based on Space: Above and Beyond.
Excuse me if I sound a little cynical.
I am tried of follow up mini series that are suppose to solve everything, like with the Pretender.