When Facebook drove a truck of money to 55 broadway and closed down their forum (where they did reply to questions around 25% of the time), was there any type of agreement that they would help out answering questions or moderating? I haven't seen a single Facebook employee since the mini site launched and some of the questions simply can't be answered by non-employees (and thus I usually vote as off-topic). You would figure they would at least show some kind of commitment for the first few days.
From the Facebook developer blog.
Many Facebook engineers actively participate on Stack Overflow, along with some of the most knowledgeable Facebook developers, making it one of the best places for you to get help with your technical questions.
A quick query reveals 20+ Facebook employees registered on Stack Overflow, with a few hundred posts between them including a couple since the Facebook Stack Overflow announcement. Nearly all of these accounts existed before the Facebook Stack Overflow project was discussed, they aren't a direct product of the partnership.
If you're asking whether they've been given a quota to answer a day or something like that, no of course not. That's insane for the same reasons LOC is a crazy measure of productivity.
As an aside, any question on any technology that cannot be answered without "inside knowledge" that only an employee would have is generally not allowed and should be closed* either as too localized or off-topic. The same standard applies to Facebook questions, naturally.
*Part of this is because these questions are almost always speculative about the future. It has to be completely clear that a question expects an employee/inside answer though, just thinking an employee should answer is not sufficient grounds to close.
As Kevin mentioned, many of us have been part of the Stack Overflow community for some time.
We care about it as much as anyone else on this thread and it is one of the reasons we want to spend even more time here.
Our goal was not to do something special for Facebook (we don't get any special privileges because of this partnership), but to support our developers the best way we knew how: on Stack Overflow.
Each week, we publish the number of questions answered on our Developer Blog. We also try to make it clear to developers where they should seek support on our Support Page (http://developers.facebook.com/support).