Gmail inbox is really 5GB?

How much free storage space does Gmail really provide? If you haven't noticed, there's a "New! Gmail Labs" link on the top of the Gmail page after you've signed in, right next to Settings -- here's the link. It opens a page which claims

It's a Gmail party and everyone is invited!
You can still invite your friends to enjoy Gmail's spam protection, 5GB free storage and other great features, but now you can also just tell them to visit www.gmail.com and sign up without an invitation.

5GB? What about this, then?













I'm confused: so is Google actually providing 5GB inbox space for Gmail users? Compressed or uncompressed? In any case -- not the reaching-out-to-never-ending size it says? Someone please clear me up here.

I'm not expecting a response from Google, though. After all, they still seem pretty undecided about Notebook, and hey, even Blogger goes on unpremeditated sleep mode.