a) A is a Linux guru, he's one of Maemo stars, worked on many projects and is someone respected. He wants to use MeeGo to install a newer kernel on it, experiment something or develop an app for it.

b) B is a "power user", he doesn't know any programming language or a newbie about that, does have some GNU/Linux experience, knows how to follow a manual page and using XTerm at least. He wants to use MeeGo for daily purposes (Web,Phone,Multimedia..) but he also knows how to deal with bugs and understands that MeeGo is still very new and buggy.

c) C is an average user. He doesn't know anything about Linux, used some Maemo and his only intention is trying new apps, games and using it's N900 as a complete smartphone. (at least as capable as Maemo 5)

bonus d) D is an idiot. He always wants the best without paying for it, he always compares N900 to some other closed device, doesn't know/doesn't care about anything IT-related and whines about his device in a regular basis. Wants to use MeeGo as a lightsaber or something.