I'd also like to register my disappointment that the slides and videos
aren't available.
When I agreed to be a speaker, I signed off on having my
talk made publicly available. There does seem to be a
double-standard here and that's concerning.
There are few things about this whole situation that aren't clear to me:
1. With what organization were these speaker agreements made?
With the developer meeting organizers.
2. Did the speakers from Apple sign the same agreements?
No, it turns out that they generally didn't because we didn't anticipate a problem. Even if they did, the speakers themselves don't have authority to release this, they generally have to check with their employers.
3. If the agreements were made with an organization other than Apple, on
what basis are the materials being witheld?
3a. That is, do the Dev Meeting organizers, or whichever organization it
was that issued the agreements, already have legal permission to release
them?
3b. What would be the consequences of releasing the materials without
Apple's approval?
As I stated previously, we found out about this extremely late into the process. There is a high probability that at least some of the slides will get released in time.
4. If the agreements were made with Apple, why?
n/a.
4a. Is there a need for the community to establish an independent legal
entity (similar to the FSF or the Apache Software Foundation) to govern
LLVM development and organize developer meetings?
I agree that a third party foundation would be useful for other reasons, but this wouldn't help anything in this case.
My read of your position here is that you're coming at this from a confused angle. From my perspective, Apple has some just about everything right w.r.t. developing LLVM in the open, contributing code, fostering development etc. The only major problem to date has been around speakers at the developer meeting, which is a pretty minor issue in the big picture, and still is an ongoing debate (so it isn't a done deal).
Getting back to "it wouldn't help anything": if the Developer Meeting were held elsewhere and if the current rule was still in place, it would be very simple: there would be no Apple speakers because they wouldn't be able to sign the form. This doesn't seem to achieve your goal of making those talks public.
-Chris