So, 8th edition is incoming.
The expected release date at present is July 10, exactly 5 weeks prior to the Open. That also means preview copies are probably out 4 weeks before that per usual, for a 9 week period of people looking at and adjusting to the new Fantasy rules prior to the Open.
So, what do we do?
Play it safe - go with 7th edition, a system generally unpopular and requiring an extensive composition system (with 2250 points level played by some armies at 2600 and some at 2000), but where people for the most part don't have to rebuild their armies to fit the tournament (except that to fit into the comp many may have to).
Play it new - aggressively study and react to the 8th edition rulebook, put up a FAQ for any of the likely errors / etc., and go with 8th edition, loosening the painting/wysiwyg requirements just a little to encourage people that they'll have their army changes ready
There are pros and cons to each of these, and it presents an interesting question for a tournament organizer
7th edition Pros
Safe and known - we don't have to come up with much of a FAQ, we have a "tested" comp system in the form of ETC, and most people know exactly how to build an army in 7th rules and how their army books work; pro of "don't have to change their armies for tourney" is mitigated somewhat by the fact that we have comp, so that's not really a "pro" or a con
7th edition Cons
A widely unpopular Fantasy edition is now replaced, with the rulebook viewable for 9 weeks prior to the tournament, meaning people may not want to waste their time and $50 + travel going to a tournament to play a defunct, disliked edition that uses a comp system to boot
8th edition Pros
New system used in a major GT may generate interest and sign-ups from people eager for something fresh and new, and eager to put their new army list ideas and armies to the test in a system where less people have number crunched it into the obvious power lists / etc.; most probably will be a better liked edition due to any glaring problems not yet fully realized (or maybe there won't be any)
8th edition Cons
People not wanting to sign up for a tournament so soon after edition releases; more rules questions the day of if the tournament organization team doesn't properly evaluate them all and address in a FAQ; again though somewhat irrelevant due to use of comp for 7th ed, people have to build new armies due to deep structural changes to the game
What do ya'll think?