What worries me is two fold; first that Moussa Koussa will not necessarily tell the truth about any of the above events as he is looking to save his skin and maybe advance his career (to become the interim President of Libya?) and so will only reveal what he thinks he has to and secondly this Conservative government lacks the killer instinct (that Tony Blair and Gordon Brown's government's had) to push for all Moussa Koussa knows about the invoilvement of the last Labour government in the release of al-Megrahi etc. In a similar situation the last Labvour government would have tried to get as much dirt as possible on the Conservatives, David Cameron and his team seem to not want to play as dirty and just as in the last election they will suffer for it.
So whilst Moussa Koussa's defection looks like good news, I have my doubts as to what will result from it will be as advantageous to the truth coming out as people are hoping.
PS: It seems that I have misspelled 'involvement' in the above, however the misspelling seems somehow appropriate for the matter being discussed, so I have left it uncorrected.