Thanks for all of the feedback over at our site.
Since we released, we have added many more features and tutorials. So, if it was no so clear a few months ago, I think you can see the direction that we are going.
Here's a link to the tutorials: ThingSpeak Resources – About Things | A Hans Scharler Blog
The biggest addition to our apps is called ThingHTTP - which allows you to send a simple command to the app, then the app does the connection to the resource that you want to get or command. It also can parse the response so you don't have to have an XML or JSON parser on the arduino. We hope that it simplifies connections to web services and saves code space on the mcu.
We also released the API to GitHub, so you can roll your own "ThingSpeak" on your home network.
Have fun!