Ravey Gravey Davy:Anybody- I mean the question is more relevant than how much do you drink as far as the website's aims go.
Oh I dunno.
But as TYP says, it sounds like whilst you've imported the playlist, you haven't actually imported the files themselves (the exclamation mark is a giveaway). Have you added the files that are currently in WMP to the iTunes library? When you do so, you'll probably need to leve them where they are (as opposed to consolidating them into the iTunes storage location, since I'm guesing the playlist file will be pointing at thhe old WMP storage location).
Lastly (grandmother/eggs) - the files are actually in a format that iTunes can read, I take it, and not WMA (for example)?