It's actually really not per existing naming conventions. Up to this point, processor cores each contain an integer core and a floating point core in a 1:1 ratio. To your point, there are actually 12 physical processing cores, but again, per conventions, an octo-core should have 16 total in 1:1.
AMD is hedging their bets as they are behind on the miniaturization process so they can't cram as much into a processor in a given die size constraint, so Bulldozer and co. emphasize integer over FP, as that is presumed to be the majority of one's processing. Each AMD module, which some consider to be true "cores" hence only 4 (I both agree and disagree with this in a sense), contains not 1 FP and 1 integer core, but rather 1 FP and 2 integer cores in a 1:2 ratio.
So what you really get in a "octo-core" like the FX-8350 are 4 modules for a total of 4 FP cores and 8 integer cores. Based on previous naming schemes, an 8 core would have 8 of FP and integer each. So like I said above, the reality is somewhere in between and you might consider it more like a 6ish-core-with-different-FP:int-ratios, as it's better than the old definition for quad-cores but cutting corners a bit too much to qualify as 8-core under the old definition/conventions. Hence, the confusion, disputes, and marketing mumbo jumbo.
