Hi, I found nice article that will guide you through the whole process. It is talking about installing libraries for a new flashplayer version in general, don't get confused by the "10.2" he's referring to.
Very informative post, but unfortunately it didn't work for me... I've got Flash CS5.5 which already lets you publish to 10.2- However, I downloaded the latest Flex SDK and copied over the version of globalplayer.swc to my config but it made no difference.
Maybe you can only build for Stage3D with Flash Builder right now? It just seems there must be a way to update the AS3 sdk for Flash CS5.5 to find the Stage3D classes.
I followed the post myself, basically just replaced every "10.2" by "11" and works for me like a charm. Did you edit xml files?
Thanks I got it to work... I think what happened was I downloaded the latest flex SDK but it didn't really have the playerglobal.swc I was looking for....
Here are the steps I took, just in case someone else hits the same wall I did:
Go to the Adobe Downloads page, and get the latest 'playerglobal.swc': http://www.adobe.com/support/flashplayer/downloads.html
(You have to scroll down to see it)
At this point I followed the instructions on this page: http://www.swfgeek.net/2011/09/26/targeting-flash-player-11-rc1-air-3-rc1-in-flash-profess ional-cs5-5/
(Very similar to the blog posted by Peter)
I'm wondering in a more general way how us developers can keep up with Stage3D API changes that occur with regard to AGAL. Since we have to import the AGALMiniAssembler from a locally saved file (I use FlashDevelop btw) how can we know if it officially changes? For instance, I've seen posts referring to a number of undocumented op-codes that may or may not be implemented, notions of branching or looping capabilities, etc. I've seen Lee Thomason's GitHub page https://github.com/flashplatformsdk/Flash-Platform-SDK/tree/master/src/com/adobe/utils but have no idea how that ties in to official Adobe releases. Also, since Flash Player 11 went live, there's no link through the Incubator site to Stage3D-specific forum discussions any longer. So how do developers stay apprised of changes that occur from now on at the AGAL level?