Actually, I found a way to do this in 3.0, but it isn't what you'd call easy. First you need to make a registry change to tell StatServer to start breaking workgroup/queue data down by Skill (this has to be done seperately on the primary and backup in a switchover environment, as it is not replicated). There is a KB article explaining how to do this available from ININ.
However, this only makes StatServer start logging the Skills data (and only at the workgroup level). If you then want to pull that new data, you have to write custom Crystal Reports to access it.
From what I'm told, in 4.0 Interaction Reporter will allow you to customize the canned reports to include Skill data, without the need to change the registry or write custom reports from scratch.
Thanks