I have finished 3 of these dragons now...a little bit of info:
Swamp dragon - 6 people (bard, 2 clerics [one botted by me], rogue, SK, enchanter) - cake. Gear on average was PoTime gear plus some Qvic. 2 clerics make this guy really easy. One does the occasional CH on the tank, the other handles group heals for the DoT. Despite 530 in all resists, I ended up having the DoT on me nearly the entire fight (due to how long it lasts, and how often if fires, this is pretty inevitable.). Worth trying to resist? Probably not. All these fights take a bit if you don't have much DPS, so I hope your cleric(s) has a decent mana pool. Bard slows landed every time with HoS before an atempt (had chanter slow but was just testing it's resistance for this post). Oh, and there is no lifetap (as previous post stated).
Stonebrunt Dragon - 12 peeps (Time/Qvic geared). A bard in each group makes this guy a chump. VERY easy to resist his stun/dispel. I would still bury the good stuff at the bottom of the spell box to give you some room for error. I think I may have lost 2-3 spells the whole fight. Slow landed no problem on this one. If you have 2 clicky items (apply as first buffs, of course) you should have no issue with losing you buffs on this guy.
Plains Dragon - 18 peeps (Time/Qvic geared). I thought this guy sucked, until we learned how to do it. He has a really nasty AE which dispels TWO every time it fires (about every 20 seconds?). It can be resisted, but even with 530 in all buffs I was getting ganked by this thing about half the time. I used my 2 clickies every time I was hit, and the dispel never got into the meat of my buffs. Once everyone settles in, this is just a slow grind to the end, but DPS is pretty key (regens about 1.5% per tic when not agroed - ? high in fight regen?). Our casters/rangers found out after a wipe that they can still land thier spells/arrows while keeping out of range of the short range AE. This was KEY to winning, imo. our shaman WAS able to get a slow to stick with the help of the all powerful Harmony of Sound, but it took a few tries.
Forest Dragon - Haven't given this guy a shot yet (heard he sucks!), so I will have to post again later.
One final note: Pulling. The spawns are BUGGED right now (at least in NK and SB) and 3 copies of the PHer are spawning at once, all on top of one another. These CANNOT be mezzed, CANNOT be snared, and there is no sense in lulling (? if they can even be lulled) since they are right on top of one another. When you pull them and fade, they will always IMMEDIATELY turn around and start walking back, so they cannot be split that way. There are only 2 ways of getting these guys split, as far as I can tell:
1) Highsun - pull them away from spawn and Highsun the adds back to their spawn, fade, then pull the solo to camp.
2) 2 bards, 2 monks, bard/monk combo - pull the PHer, have other puller tag one away. Once split, both fade off agro, then reagro the solo.
Hope they fix this bug soon.
Desflurane