So i'm confused as to what this camera is, actually.
In a normal d/slr, there's the mirror, which projects light upwards, through the prism, to the eye. Then the mirror is also kinda translucent, some light goes through it to a secondary mirror, which projects the light downwards where the AF sensor is. That's why AF sensor can't go all the way to the top/bottom edge, basically this second mirror also has to flip up too. In all that, i'm not sure where the light meter is. In old-school cameras it was in the prism, maybe it is these days too.
Now, an SLT or whatever they're called, there's no prism, and the mirror is fixed. When you put your eye to it, you're just looking at a small screen. So the AF points are at the top where the prism should be? And there's no metering sensor, because the sensor is on all the time for the 'viewfinder', it meters with it too?
Now, this a99 has me puzzled. If there's an AF sensor at the top, and the mirror is fixed, why have a J1/650D/EOSM-type sensor with AF points dispersed over the sensor? It's redundant. We already know that Sony's earlier SLTs could full-time video AF (at least, until the sensor overheated), why have a hybrid AF-in-Sensor too?
Unless there is no mirror at all? Then it's just a Pentax Q style mirrorless-in-a-dslr-body? Why not just make a bigger nex-9 with a smaller flange-distance and be done with it? (at least that way, they can make a FF body that takes any FF lens ever made, and sell a metric S___eload).
Still, if, for some strange reason, they do have AF on the sensor and AF up the top, are they counting both towards that '102 AF points'?