Oh, what's this? A player smears the reputation of another at the beginning of this thread, then, after much discussion, establishes that "he is actually a great player." I'll wager you regret your quick judgement, stormwolf.
I agree with Chris here, but acknowledge that diplomacy will always be split, between metagamers and single game purists, between reputation-smearers and those who keep their precious precious knowledge to themselves, between people who form tight alliances and those who prefer a more fluid style of play, allied with everyone and noone. Oh, and of course, those who for whom a 'place', like second or tied first is a good result even if it is currently hypothetical, and those who will try to win whatever the cost.
Personally, I prefer phpdiplomacy without the ability for joint wins- it forces alliances to be broken and for cunning diplomacy. If it has a downside, its that it seems to encourage metagaming (psst, we can't draw, so let me win in this game and I'll let you win in another.)
TOgilvie