Personally I think the DG boss is now more on par with the other NiM bosses. Yesterday we did our first real tries on the DG boss ever since the week it was released and we downed it. As a healer I completely agree with the fact that the fight has lost much of it's healing intensity. One time the only reason we died was because 5 people in a row (yes 5!!!! first 2, then 3 more) got a red circle which we as healers could no longer keep up with. Keeping both tanks alive and 2 people with red circles, of which one had wither too, at the same time was NO problem at all. NONE.
To be fair it is still harder to us than the 3rd and 4th boss but I guess that's because we had a lot more practice on those than we had on the DG's.