[advis0r]

i agree that player stats should not be included right now.

regarding the win/loss info:
this information is present in EVERY handhistory, the only difference between sites is how it is encoded.

some have a summary section that shows each win/loss, others dont have this section but still indirectly contain the information.

so i dont see a problem with including the win/loss info in the standard, because you dont want to throw away this information if the site gives it to you and its included in every HH anyway.
(the parsing and correctness of this info is just moving up a level from the 3rd party applications to the XML creator)

i agree that there should be something like a street tag with an attribute indicating the order and maybe an optional attribute indicating the name (i.e. Flop/Turn/River for holdem games).
this makes it easier to support stud and draw games.