Today, Steve Ballmer announced at the Web 2.0 Summit that Popfly has moved from closed alpha to open beta; we've lifted the invitation-only restriction and anyone with a Live ID can now browse to the site, create an account, and start building and embedding mashups. So what's new in this release? The Popfly Team blog has a good list of features, but the one I'm happiest with is the performance on embedded applications.
We accomplished this by changing how we store and retrieve mashups. That pig mashup I embedded earlier I resaved and the load time reduced by half.