>I'm pretty sure it's an april fools
joke from google.

I think it's legit. It's now April 4 and
the offer is still up. From the FAQ

10. Why is Google offering email? I
thought you were a search company.

Google's mission is to organize the
world's information and make it
universally useful and accessible. For
many people, email contains valuable
information that can be difficult to
retrieve. We believe we can help with
that.

And they specify 1 gig of storage. It
seems messegages never get deleted and
will be searchable, hence the need for a
lot of space.