Now looking at the features, what's the difference? Mainly easy signup, basic reporting and "Create and run a single ad with many keywords" and Google chooses the CPC for you. In other words, strip away the complexity and just get an ad up.
Now I only read through the docs, but I found this interesting concept: AdWords Health Meter. It's pretty much the same status as regular AdWords but it's explained in a warm & fuzzy way.
Of course, just like "marijuana leads to heroin", AdWords Starter is clearly designed to get you into AdWords Standard. And once you upgrade, you can't go back.
The key takeaway is that someone over there cares about the great unreached masses of PPC newbies.