I've been using my d5100 (first dslr camera) for a couple years now, and am looking to upgrade next year or maybe even later this year. At first I thought about switching to Canon because of their lenses, but I've decided I'll be sticking with Nikon. Eventually I'd like to go pro, so for now I haven't decided what kind of photography I'd like to do. I thought the obvious choice would be to upgrade to a full frame camera (probably the D810), but now with the D500 looking like it's one of the best cameras out there I might go for it first, then wait for the successor of the D810. I'll have the mini D5 AF, 10 FPS, and what so far looks like great ISO performance. I don't think full frame is always where it's at. If I treat a crop camera like a crop camera instead of a full frame one, it should give me some great images.
Great plan BUT - let me throw a wrench in it The D500 is $2k You can get a refurbished D7200 for $650 maybe as high as $750 and those are regularly at that price refurbished from Nikon... and you can pick up a used second hand Nikon D750 between $1300 to $1400. So for slightly more than the single D500 you could get two cameras with similar layout and knock a punch into both full frame and crop - providing yourself flexibility and backups to each other....
So for right at $2k or slightly more in some cases depending on your patience... you could get a double up on the bang for the buck, and as much as I too thirst for the buffer on the D500, will you NEED that buffer? For most of my shooting the buffer on the D7200 and D750 is more than enough (except during dance recitals and usually only 3 or 4 times per evening is it an issue lol)
BTW the above was my end result because originally I was going to sell my D750 and get a D500 but decided gripped D750 + gripped D7200 made more sense at similar price point for me and then I can wait for D500 prices to drop and for the successor to the D750 or D810 to come.