I do remember them having some freebies and stuff at previous ones
They give you a track jacket and that is IT. The track jacket does not have pockets. One year the did give away a nice, if simplistic, backpack. Unlike many other conferences there are no vendors, hence no other free stuff.
Otherwise, I'm not sure what the point is if you already know how to use the APIs and don't have a problem reading about upcoming changes online.
There are a few points of value that have diminished. The first is that the WWDC sessions have usually a lot of good demos about HOW to use the new technology, which is quite a lot more useful than just reading about the raw API. The second was that people used to ask questions after the presentation, which was not on the video - that was done away with last year though, which is a real shame as the questions were often full of insight about the technology and potential issues.
But since as noted they stopped taking questions, and you can also see the videos a week later that reason is not as prominent (though it doesn't hurt to be a bit ahead of the curve).
schmooze your way into Apple employees' good graces?
That's not really a reason to go as it will not do much for you. But what is still valuable there is that you can talk to Apple engineers directly responsible for the different frameworks across the iOS API. These labs took some time to get to someone who was really one of the primary developers, but when you did reach them it could be very useful to find the answer to some deep problem.
It's also useful just to talk to other developers there, pretty much anyone who is there is usually pretty knowledgeable and has worked on some interesting stuff.
It's also good to take a solid week off work and just think about upcoming changes to the API and direction Apple is going,
Also on a side note WWDC usually has some pretty cool lunchtime speakers, last year for instance J.J. Abrams and Neil Armstrong were speakers (different days), for a few years they had a guy from Pixar with a really good talk. It's not a reason to spend some effort and $1600 on a ticket, but it is a nice break.