Review of Fujifilm's image sensor phase-detect AF is explained on dpreview so it can be done. http://www.dpreview.com/news/1008/10080505fujifilmpd.asp
They claim AF speed of 0.158 seconds but obviously DSLR AF is much faster since shooting at 10 frames per second and autofocusing in between frames must be less than 0.1 s. So at least in those fuji compacts, that system is not as fast.
Im afraind you may confuse DSLR with AF. they may be quit different concept.
To be frank, 0.16s is rather quick for a mechanism. but DSLR is a optical route reflected by prism. which can can get a accurate image positoin on the film through finder.
or say, ccd or cmos sensetivity is faster than mechanism movement which drive lens to a fit position. one is electronic, another is mechanism.
however, lens has a large mass.
I'm not confusing the two, but I can see why the way I wrote my comment may be unclear... The Fuji is a mirrorless camera and is therefore not a DSLR. So, my comment was comparing the 'phase-detect AF built into the image sensor of the Fuji' to the 'phase detect AF implemented in separate AF sensor of a DSLR'
Unfortunately, I'm not sure what your other comments are getting at but perhaps you also misunderstood why I referred to the fps of a DSLR. I did that to demonstrate that the phase-detect AF in a DSLR using a separate sensor is much faster than the Fuji system... if a DSLR can shoot at 10fps then the AF must be able to focus in less than 0.1 s because it is happening in between each flip of the mirror.
Hopefully that's clearer than my shorter original comment.