In my opinion,
The vampiric embrace spell was never an exploit. For starters, you needed either regs or LRC in the first place in addition to all the items just to cast the spell. Secondly, the -25 fire resistance, albeit small is still something that occurred while you're in the form. Me personally, I never really liked the template...not my style. Consequently, I never cared what these people did or what they could solo. That's none of my business. They're having their enjoyment...I'm having mine. That said, it was a lot of stuff you had to fool around with just to have a PvM template.
My thoughts are really, they might as well just take away +skill items because really there are tons of ways to solo high end mobs even if you just took this template away.
Me personally on my old dexxer template I could solo every lesser boss in Doom, the named changelings, any other named monster, and dark father...even if it took me a few hours. That said, they just need to leave dexxers alone is my thought. IF anything, might as well just make all the bosses exponentially more difficult. For example: after "x" amount of time, the mob starts getting its life back, harder to hit, etc. The before stated reason is why certain monsters in other online games can't be soloed.