All I know is, it will be quite difficult for me at this point, and probably other people, to be able to get the necessary days off from work, if they suddenly announce that it will be anytime in the summer. If they'd been able to do it even up until last month, at least I'd have my foot in the door.
My company has too few workers left, and too many ahead of me in line for vacation time at work. My co-workers take a lot of time, 2-3 weeks, mainly to visit relatives overseas, never mind the modest 5-6 days (which encloses the weekend in any case) that I would require, assuming the event's in California this time around.
Probably September or October WOULD be OK for some, but then we'd lose the college people, and the parents with younger school-aged children, the ones we hope will carry on the fandom. That would be a major bummer.
Watch out, after posting this, how much do you want to bet the promised Shadowgrams with the announcement will appear in mailboxes tomorrow or this week anyway? (Like how it always rains after you just washed your car....)