No more of a disaster than the parks that have lots of construction walls. Progress vs. disaster -- it's all in the eye of the beholder. We were at DTD in June and my only complaint was that I had to (excuse me...I chose to) drive our own car and park in a parking deck that, while pretty awesome, wasn't anywhere near the part of DTD that we wanted to visit. But given what they are doing there and the end game, that wasn't really a big deal, especially knowing that we chose to drive instead of taking Disney transportation. Lots of new stuff has already opened up and continues to do so. Once you are on site and walking around, I think it's actually already better than it used to be.
I suspect that the whole construction complaint will continue to a reasonable degree between now and 2021, when we'll see the 50th anniversary of WDW. As 2021 gets closer, projects will be completed, walls will come down and we'll have a year of minimal complaints (at least in the construction area). Sounds like a long time away...but not really.