Nice pull, I think you have lots more in the tank still.
Awesome speed off the floor.....with this weight I did notice the little hitch at lockout. What a lot of guy with crazy speed off the floor and through the middle of the DL do is straighten their legs as the bar nears their knees, this gets the bar moving, but the problem is that the hips are then in a poor position to be driven forward to finish the lift, and when you lock out a heavy deadlift, you really get more power by driving the hips forward.
Now, I watched your vid at least 5 times and on that particular pull you look to have straightened the legs a little bit too early.....now, thats fine, I have pulled some of my biggest DLs almost straight-legged as has most anybody who has ever strained to do a DL.....but, if you reach a point where the bar is flying off the floor like mad and you start to miss at lockout because you can't drive the hips forward, then you'll need to make a conscious effort not to straighten the legs so soon.
As for 500lbs, I think it is as good as in the bag, if I were a betting man, I'd bet if you took off next week from Deads you could come in the following week and hit 500-510 no problem.