DPS...
From what I've seen, an Assasin does a lot of damage over time with their low delay, dual wield and poison (poison is very important) mixed with some medium burst type damage from positional attacks and the occasional very high burst damage from stealth type attacks.
As far as how good the burst damage is, they have the highest melee hits in the game so far. The higher end damage abilities (stealth) are usually have lengthy timers. The medium ones (positional) have pretty short timers and do pretty respectable damage as well but not nearly the amount of the stealth based attacks.
Check the stats yourself:
Highest Melee Hits Edited, Mon Nov 29 10:52:01 2004 by subvert