I honestly think wgt intended on using the "wgt nation" thing to combat cheats but never really followed it up. I may be wrong but i don't think a cheat would join the wgt nation, especially a multi accounter.
What i think wgt need to do is scrub everyone from wgt nation and start again. Except this time players need to show some kind of proof of what they use or don't use as the case may be (not sure how this could be done but i'm sure someone more pc savvy could tell us). Names and addresses need to given for everyone who wants to join with some kind of proof of I.D.(photo of driving license or passport or other form) Then only players in wgt nation could play for credits or other tournaments.
Just an off the cuff idea but i think it could work. I love this game and i'd hate to see it disappear through players not wanting to play through fear of being cheated.