Ian Thomas posted in his blog, that Microsoft has setup a new beta request form for the new Microsoft Analytics tool, Gatineau.
So if you want to be a beta tester, sign up for Microsoft Adcenter ($5 signup fee) and use the same email address to fill out the Gatineau beta request form her.
If you already are an Adcenter user, just use your Adcenter emailadress for the request form.