I am by no means convinced that automatic selection of sources other than that based on the most obvious, automated, criteria, is wise or needed. We have had for many years, in QuickTime, this facility, and quite a few sites opted not to use it and allow the user a manual choice instead.
For example, bit-rate is important when watching a streaming movie (it has to arrive in time), but many users wanting to watch a trailer loaded over HTTP apparently choose to put up with longer downloads in order to watch higher resolution content. Offering the user a 'quality' based selection is, in a sense, pointless; why not show the user the best quality (all other things being equal)? The answer is that they aren't - that bitrate (sometimes) matters. David Singer Multimedia and Software Standards, Apple Inc.
