I am not sure if the following has been posted somewhere sometime already, but anyway... There we go:
"I would like to know if it would ever be possible to have our other PvE characters other than the current PvE characters we are playing (if this makes sense to you) as part of selectable hero?"

For example, instead of picking Koss (sorry dude, I had to pick one and you're the first one on the list) why couldn't we pick one of our PvE character that we have?
Mind you ask me why so? Well, the more I see it the more frustrating it becomes obvious. I enjoyed playing Guild Wars. Make first char, then moved on to Factions. Make second char, then moved on to Nightfall. What are the chance I will play Nightfall with ALL my "old" char...
Overall, I think it would help connect even more all the "expansion" of the game, don't you think so?