I joined a 25m PuG the other day hoping to clear heroic ToC.
As per usual, it was fairly straightforward until we got to Anub - Leeching Swarm got the better of us every time (not that it was even one of the better PuGs I've been in - out of the 10 or so tries where I repeatedly mentioned the fact that the adds need to die first, not once were they all dead before Anub was pushed into phase 3).
Even though the PuG failed to kill him, the attempts left me feeling that if it was a guild run, we would have been able to do it. Definitely not easily, but doable.
What's more, Durendil, one of the pioneering epic hunter soloers (bless those people!) recently uploaded a video of a solo heroic 10m Anub kill.
Unfortunately, not all of my guild are as enthusiastic about Achievement hunting as I am (I know, it's terrible that not everyone has my OCD! :P), so I tend to have to resort to PuGs for this kind of thing and hope they don't fail.
Of course, PuGs being PuGs, every ToC PuG I've joined since hitting 85 has failed at Anub. Oh well, perhaps I'll be able to solo the 25m version when I'm level 90....