The first is the YouTube model. Land on a page, hit play… there it is.
The second is the personal-computer-free experience.
In this second model, the device might _be_ a computer, or it might require a computer (or a server or whatever) to be on the local home network, but the point is that you dont need to go and sit in front of a computer to consume the media.
The squeezebox is such a model. The iPod Touch is this model (buy a tune from iTunes, directly from the WIFI-connected iPod Touch, and play it directly). The AppleTV is such a model (it seems to be a flop). Amazon’s Kindle is such a device. There are many more.
The second model essentially aims to remove the “sit in front of your computer launching applications” experience.
People don’t want to sit in front of their computers to listen to music. This has been expressed on the Sursound list repeatedly.
The first model (hit the web page and click play) will be implemented in he next version of Ambisonia. The second model is far more difficult… but one could argue that it is what we should be aiming for, long term. It is more difficult because it requires a “device” … a squeezebox like device.