We just booked our airfare this morning for our trip next June. I really only did it this far out because I was using my Marriott rewards points to pay for the flight. Our
budget was counting on getting the airfare for free through my rewards so we wanted to make sure we didn't miss out if availability for redemptions is limited. We also knew that we want non-stop, the airline (United), and time of day (early morning to MCO and late afternoon from MCO). We already knew the flights that met our criteria so waiting didn't seem to be in our best interest.
While there is a chance that the times will change over the next 10 months, hopefully the changes won't be too significant.