Oh, alright. After posting my dwarven thrower questions, I went to check the Stoneblessed PrC. At 3rd level, it gains the Stoneborn ability, which states:
"At 3rd level, a stoneblessed completes the bond with her chosen race. The stoneblessed gains a permanent +2 increase to her Constitution score. In addition, for all effects related to race, a stoneblessed is considered a member of the race to which she is bonded. For example, dwarf-bonded stoneblessed are just as vulnerable to effects and abilities that affect dwarves as actual dwarves are (such as a ranger's favored enemy ability), and they can use magic items that are usable only by dwarves. The stoneblessed meets any racial prerequisites for prestige classes and feats as if she were a member of her bonded race. Finally, the stoneblessed gets an ability based on her type of racial bond:"
Again, it's not explicitly clear, but the text strongly suggests that meeting prerequisites for prestige classes and feats are effects. The structure of the paragraph, "The stoneblessed... In addition... Finally..." suggests that "The stoneblessed meets any racial prerequisites for prestige classes and feats as if she were a member of her bonded race" is an elaboration of "for all effects related to race, a stoneblessed is considered a member of the race to which she is bonded". If it was not, and it was a function of the Stoneborn ability, the text should have said "The stoneblessed also meets any racial prerequisites for prestige classes and feats as if she were a member of her bonded race" to distinguish it from the previous point. So in this case, at least, it seems that the RAW considers meeting prerequisites for a prestige class or feats to be an effect.
Of course, as was previously discussed with Hyp, the RAW are occasionally inconsistent about what it means to be considered a member of a race for the purpose of meeting prerequisites, and this argument hinges on a fine point of writing and communication. So, I don't think it's going to sway anybody with an entrenched position, but it might persuade those who are undecided.