@ darth adder: a theatrical release? for fans specifically? I'm impressed. massive kudos to that, such a move may lead me to get the dvd set and movie. I heard it was a pretty good series and so with my general weakness for sci fi stuff I'd probably even be happy with it. danke für den tipp und gruß vom südlichen nachbarn.
as for directions ... well, I may be the only one, but I found the season 4 finale very good. if nothing else would do, I'd like to see that future - 2761 or sth I believe it would be - visited. with two sides of earth again and the alliance still in place (though in what constitution we do not know) it would be an interesting scenario and full of possibilities.
other than that, well, I think a lot of the loose ends have been tied up either in the series or via books. not sure how much they dealt with the drakh, I wouldn't object to a plot that had to do with them. maybe a vast prequel showing either the age of valen or even more of the origins of both the shadows and vorlons could be interesting too. think about it, there could be a lot of races present that were ultimately destroyed in the last shadow war. one could see how they came to narn and mars, how they use the nano virus on that species from crusade, how they formed relations with the drakh, what the minbari were like before valen. any of it (of course not all, would be way too much).
so, you see, there are indeed many directions in the past, present and future (series time speaking) that a new addition to the franchise would go to. what I personally prefer? good question, I don't quite know. I guess some other time period than what we saw would be nice and since the humans weren't around for so long, the future would be better. hell, what about a movie that expands on the start of the all our war. bit like sum of all fears. conspiracy going on, some trying to stop it, but ultimately they fail and the war breaks out. could intertwine with what we saw in 'deconstruction'.