my name is Jan and I support Fabiana in the Season of Usability project for the SIP-Communicator. Fabiana posted a sketch of the project plan, which was commented by Emil. There is one crucial point there where I want to make a suggestion.
. Expected Users
Is this a trick question? The entire planet of course!
It is very difficult if not impossible to make software perfectly usable for everyone. And talking about "the user" can be misleading because everybody uses the same term but has someone else in mind.
As we did for the GIMP project and many others, "Personas" are a very good tool to focus on possible (fictive) users and organize the usability work around that.
Personas are fictive personalities that you make up based on the target users you have in mind, and give them as much properties, constraints, desires, capabilities and context information that is relevant for SIP-Communicator. A typical number of personas is 3. You have one primary persona, and two secondary. Collecting data can e.g. come from market research data (what users are using VoIP? Skype?; Number of buddies in a list, etc.).
What we gain then are users we can talk about, that are partially based on real data, and we can say: this is the user we want to make happy, and those are the users whom we want to use our software.
More information about personas can be found here: http://en.wikipedia.org/wiki/Personas and here: http://tina-t.blogspot.com/2005/06/personas-part-1.html
My suggestion is that fabiana and me are working on a first sketch of the personas. We will outline them in the wiki and change them according to your feedback until we agree on them.