Spree, I don't have the precise figure, but U.S. deaths in VNam in the first two years were almost certainly less than U.S. deaths in Iraq have been to date. Most U.S. deaths in VNam occurred after the fifth or sixth year of commitment of significant troops.
If my recollection is correct, by this measure (deaths), Iraq - so far - is worse than VNam after about the same period of time.
Keep in mind also, that VNam was an insignificant backwater that lacked any strategic import. Iraq is at the very center of the highly volatile Mid-east with multiple strategic U.S. interests involved (Israel, Iran, Saudi Arabia, Syria, Turkey, and above all, OIL).
Failure in VNam had little strategic consequence to the U.S. in and of itself. Failure in Iraq (which is likely, IMO, and was forseen by many and ignored by others) will have tremendous strategic and geo-political consequences for the U.S. - all bad - for decades to come.