Umm...hard to say, but I think the D.A. members will join in the aid of ridding the magical world of Lord Voldemort. But I do not think they will fight HIM, no thats Harrys job. The D.A. members will be in the background fighting all who cross their paths, which will be a lot of people and tons on magic and spells. They'll be fighting all his aids and so forth...
Dumbledore was the only man whom the Dark Lord feared, but he (bless his heart) is now dead, killed. The one man who could of helped Harry. He cant yell 'Go Harry Go' from the side lines and thus hes now dead (like I said would happen in other threads).
But YES I think the D.A. members will take part in the war and death might be around the corner for someone or all.... They got 'lucky' (lol) in book 6.
i agree with DanFan, they will have some part with the war. Rowling wouldn't just add them in the fifth and forget about them. I'm sure that they are going to have a part in the war. They were taught by the best Defense Against the Dark Arts student of his year, so they stand a good chance against them.