What really fascinates me to no end is how much time any web service needs to spend understanding the user.
Case in point... that little digital me on the sidebar. Some people didn't like that it auto-played... saying that blog readers are not used to having to deal with any kind of audio whatsoever.
That may be true, unless you're ever checking out MySpace pages, which barrage you with audio and video, sometimes two videos at a time, all as soon as you load a page. In that community, jarring as some of us may find it, that's the norm.
Why is it ok to present an audio experience on MySpace but not on my blog? Is that because you're reading in the office? Is it just a generational thing where most people under 25 watch TV, listen to the radio, instant message and do work all at the same time?
Of course, there's no right answer, but if you're a web service, it certainly presents a difficult challenge. Avatars aside, anyone who wants to get penetration throughout the web has to decide how they make their platform flexible, but not confusing and certainly not so flexible that it fails to establish a uniformity of a brand experience.