(Edit note, it looks like I am in error)
Whenever I am asked to sign in for a "new" or "upgraded" service, If I bother to click on the link at all, I ALWAYS check the URL ADDRESS.
For instance. I recently received an invite from "Google Base". But the link URL the email provided looked like this..
If the word Google is not immediately after the two forward slashes, I think that means it is a Phishing site looking to steal your information and perhaps do you some kind of identity theft or some other form of harm.
If you want to cut and paste the URL from above you will see that the site looks just like google base, but if you then google "google base", you will find that the word google is indeed directly after the two forward slashes, like this...
http://www.google.com/base/I hope you were not "phished" upon by the presumably fake google base email before reading this post.