We created those single service plug-ins just to make it easier for users to find them and to fill the void of all of the service like YouTube that would be missing at launch for the N900. You can read more about it on the Nokia Blog at http://thenokiablog.com/2009/12/21/p...ns-nokia-n900/

We've also introduced the ability to authenticate an account based on your Nokia Share or Twitter credentials so you don't need to create a Pixelpipe account if you don't desire.

Hope that helps to clear things up a bit.