I would agree with those commenters that said buying further out seems to yield better prices for me. I've planned and bought tickets for trips to England and France and there were no last minute deals, or even 3-4 month out deals. I've just watched prices climb with my Google Flight alerts (there may have been some minor fluctuations, like saving $100 bucks on a flight, but nothing extreme, and as soon as they lowered, they raised again a day or so later).
Unfortunately, I can't just wait and buy tickets for whenever prices are cheapest. It does seem like waiting could yield deals if you're flexible on timing, but I'm not, due to kids' schedules, work, etc. Plus, we have to buy five at a pop for our family (yikes!) and we want to minimize layovers, length of flight, be able to select seats, etc.
However, I do appreciate the reminders that if I do buy really early things may change with flights! Thanks to everyone who weighed in... And I may not rush to buy tix as soon as they release them for next summer, but I will probably buy at least 6 mos out.