There can't (and likely won't) be any true consequence to a public raid/group due to bad play of others. Because if there was serious consequence it would make the game basically unplayable. Difficulty will probably be relaxed & scalable enough to allow actual, um, playability given the general chaos of 20+ people running around with varying skill levels and attention spans.
Which is about what I expect challenge wise for DEs on live servers and more or less the best way to approach them; Jump in, jump out. Take a bathroom break. Kill stuff. Have fun.
DEs as fun things to do instead of static world dullness.