According to http://live-tennis.eu/race
The current cut-off for points is 6155, with Andy on 5160, but you have to remember that the cut-off is fluid, and has to allow for all possible combinations of points being allocated to the players in the running, so it has to include Andy winning no more points, and the player currently ranked 9th winning every possible point going from now until November.
So as the year progresses, and tournaments pass and points being allocated, the threshold drops, so there is a good chance that by Toronto, the threshold will be lower than Andy's existing points, never mind what he gains there. By November, the cut-off will be closer to 3500.
However, there seems to be a rule that if a slam winner doesn't qualify in the top 8, it's the top 7 plus the slam winner, so I think the very worst case scenario for Andy not to qualify would be if the winner of the US Open doesn't qualify on points, yet still finishes the year ahead of Andy. I expect that's a mathematical impossibility.
In other words - Andy has already qualified, but they'll wait to announce it in Canada or Cinci as it's an extra excuse for a news story, so extra publicity for the event.
Regarding Race Rankings - they are essentially "points earned so far this year". It's all bit artificial, but so long as you remember what it actually is, it can be interesting. It's inevitably skewed in favour of players who do well in the early part of the year, so it makes clay court specialists look good. That's why i don't think seeding has anything to do with the order in which you qualify.
As the year progresses, the Race/Year to Date rankings look more like the regular, rolling annual total, rankings. Later in the year it's easier to use that to work out who might become Year End #1, but right now, you really need to look towards the real rankings to get an impression of how well a player is predicted to do in the next few months.
Obviously, Rafa didn't earn any more points towards his regular ranking from now on, and everyone else has Olympics points to lose, but historically, this is the period where he struggles to earn points at the same rate as his rivals. The biggest unknown is whether or not the time out will mean he does better this year, or if he's still got niggling problems. Could it be he didn't bother trying to adjust his game to grass, hoping for the best, but planning to make gains on the longer hard-court season?