Honestly. If you need a gig (!!!) to store your web-based e-mail, you need to learn to archive, or just
LET GO of the old stuff. 20 MB is fine, though I must say the gMail GUI is a lot cleaner than HotMail. As for me? I just run my own e-mail server so I don't use either.
Also, I think there is a very real possibility that people will simply use gMail as free storage space for application files, and other binary attachments. This of course opens up the wherez possibilities, which I think need to be seriously considered. There are going to be corporate liabilities with this much storage.