Great deal eh? I picked these up this past weekend at my local spring fish auction along with a rather nice light for a planted tank I have going. The only bad part was that the cooler I brought wasn't big enough as these guys were frozen flat and my cooler was more cubed. Which meant that when I took a detour to the race track to bet on the Ponies racing in the Kentucky Derby they started to thaw. Not so bad, if you don't mind your kitchen smelling like a bait shop on a hot summer day.
So, Bloodworms, good, bad or indifferent?
Before 3.1 they were considered a leveling talent as they soaked in healing and would sometimes run off to go attack another encounter of baddies down the hall. The psycho temperament has been fixed, but they still will soak in healing. However, with how AOE heavy encounters are in Ulduar I really don't see that being an issue because they'll die before they're able to lap up some heals.
So what would you give up in order to get Bloodworms? - Mark of Blood and Vampiric Blood - Both of which consume a Blood Rune and a GCD.
How much DPS do your worms do? Not much, reports coming in as little as 30 DPS to as high as 90 DPS. So lets put this all together...
30-90 DPS Increase > No DPS Increase + Consumes Blood Rune + GCD
I use Vampiric Blood as my "Oh shit!" ability, but usually at that time it's a wipe or going to be, so I don't get much use out of it. My role in a raid is DPS, so if I have 2 floater points I'm going to put them into something that can actually increase my DPS.
TLDR: Bloodworms r gud mmkay?