check the main gmail page, it shows storage increasing byte by byte.
Also, on April First, they introduced the new storage plan (nope, not an April Fools joke, gmail was released April First). The new plan is called Infinity +1. They were increasing it to 2 gigs that day -- and doing so pretty quickly, at that.
And now its slowly increasing, by around a meg a day. If that keeps up, nobody will ever use all of it.
Which is kind of the point. They've abolished the need for users to be concerned with storage space. Its not as if they actually have a spare 2 gigs for all of us on the server farm, and if we all suddenly used 2 gigs they might not be able to keep up with it. Like withdrawing from a bank.
Edit: Spelling!