After reading his glass options, I'm thinking a single IV and a round of upgrades to his 24-70 and 70-200 IS, plus a 6D? Having 2 identical bodies makes moving between them much easier, but it seems that you're all over the board, and sinking your entire budget into a single X isn't going to solve all your issues at once.
Not that spending money isn't fun, but hitting these upgrades now would make adding a 1Dx in a year just that much stronger overall.
I thought I was clear that I need to shoot both indoor and outdoor action so upgrading lenses I already have and getting a 6D will not provide a solution. Thanks for your input and for everyone who stayed on topic, you gave me tremendous insight. Since I have a respite between fall sports and late fall dance performances, I can wait a bit for the purchase. I have 2 more CPS 1Dx loaners to cover anything that may come up that I can't cover with my 5D2 and 70D. I know I can't cover volleyball in the venues I shoot so I think I will opt for a 1Dx just before volleyball season starts. Hopefully, Canon will have made announcements before my next purchase and drive the price down. If the announcement means I wait for the new camera rather than the 1Dx, then I can rent as needed.
I'm sorry if you didn't read it that I started with getting a single IV - aka 1D mk4 - and spending the balance on the lens upgrades. You seem to be overtly demanding on the performance of the bodies, and getting an extra FPS or two seems to be critical. Might I recommend you consider the AF drive performance while tracking of your current lenses - a 1Dx may be held back by their af speed especially if it's looking for focus confirmation.
You're already talking about limping along with your 200/2 - outdoors, so I'd also point out you're better off with a 300/400 2.8 IS lens otherwise you lose any of that added fps.
I don't disagree that the 1Dx would be all that you want, but you came here looking for opinions, and my opinion is to get the 1D mk4 and upgrade your glass.