Here it is what I did:
1) I exported my wordpress blog. You have only to login to your WordPress account, navigate to the Dashboard, look for the Export link. Wordpress will produce a WXR file (Wordpress eXtended Rss) which you will be able to save to your local machine.
2) Go to Wordpress2Blogger, browse the saved WXR document and click Convert and save that file to your local machine. This second XML file is a blogspot specific file.
3) Create your blog on blogspot.com and choose the XML export file you just produced in the Import Blog Tool. Alternatively if you already own a blogspot blog, go to the panel, choose the "Settings -> General". On the first row, immediately before the "Title" filed (yes, it's just a little hidden) there are import and export links. Just click on import and you will see immediately all your old posts and comments
4) After creating my blogspot blog, I wanted to integrate in my site, using my domain name and my look and feel: to do that I just configured the great Rapidblog plugin from Loghound software in my Rapidweaver project. You basically only need to give the blogspot username/password to the plugin.
Et voilà, a complete blog migration in less than one pomodoro! Bye bye wordpress.