Adobe's MAX 2011 conference took place last week in Los Angeles. During a Q&A session, WebM support in Flash was talked about. After Adobe was questioned about the WebM support, the response was, "Yes, on the priority list it's not very high because we don't have a lot of customers or real customers who want to do production with WebM. The problem on the production side is that encoding WebM is simply too slow, it's not real time. And it's not JDI too (just do it). Yes, it's a lot of work for us."
This came up during "The Incubator: Test The Bleeding-Edge Capabilities Of The Flash Platform" session. The MAX 2011 video is embedded below for reference.
This will upset some proponents of Google's open-source audio-video format. Adobe Flash 11.2 went into public beta earlier this week and there was no WebM support there nor would we now expect to see this support in the near future. Also still M.I.A. from the Linux Flash client is support for XvBA/VA-API video acceleration APIs (right now it's only NVIDIA VDPAU and Broadcom Crystal HD) and many are still challenged by stability and performance issues with the Flash Linux plug-in. What the Flash 11.2 update does bring, however, is multi-threaded video decoding support.
A tip of the hat to the Phoronix reader "Consiliens" for pointing out the WebM information from Adobe's MAX conference.