I always wondered why they didn't have a drive mode where the mirror stays up for double or triple frames. Assuming sensor readout the shutter and write to buffer/flash could keep up, you could get 20 or 30 fps, and still get 10 FPS flashing in the viewfinder; which should be enough to track a subject under most circumstances.
+0.5. I've thought about this, too...but the times when you most want a fast frame rate are with rapidly-moving subjects, and that's when you most need AF between frames. I wouldn't want 30 fps as in-focus -> a little OOF -> a little more OOF -> in focus -> etc. Heck, even the S100 I pre-ordered will hit nearly 10 fps (9.6) if it doesn't AF between shots.
I am new to the hobby compared to you guys/pros and have probably only taken about 40k-50k digital pics so far (I have 30k on my PC plus gobs that I throw away).
In those 40-50k, not once do I remember taking a burst with an object moving towards me where I needed AF on every frame. (Not saying others don't need it), but I have never needed it... so I may be in the minority here while I say, I'd rather have 10+fps with 1-3 AF's in between.
Most of my subjects move laterally (requiring little AF adjustment in a burst situation) or are hyper-mobile hills. Now that I have said it... I suspect I am going to regret saying it