I think this is something slightly different in that it's non-blocking. The progress bar provides users with feedback as to the current status of the page they

I think this is something slightly different in that it's non-blocking. The progress bar provides users with feedback as to the current status of the page they have requested to load, but it doesn't get in users' way and the page loads and renders as assets become available (unlike in SWF where all interaction is halted until the entire site has been downloaded up front).