There are a couple of more issues that are not being addressed:

First of all, if you close out a couple of cards an you do carry balances on the others, this will raise your percentage of debt to outstanding availability and lower your FICO score

Second, part of your FICO score is based on your oldest open account - make sure you don't close accounts you have had forever

Finally, there is a bit of art to this score system. For example, we all know that too many credit requests will lower the score. At the same time however, applying for a receiving a card now and then will raise the score. You might want to go to the FICO web site and read up on all of these issues, however the acutally system is a black box and they will not get specific about how changes will effect you.