GMail is allowing us to use over 2802MB and counting as of right now, but on January 1, 2007, GMail’s e-mail storage allowance had paused and indicated that the service was capped at 2800MB (2.8GB). The service has started running again, but according to ZDNet, the service is expected to take a pause once again on April 1, 2007. The reason why GMail may has gone down on the new year may have been caused by a bug that needed to be fixed. GMail recently had a bug that may have caused you to give away your contact list information.
Coincidentally, April 1, 2004, was the day GMail was released (GMail press release). ZDNet has a few theories about why GMail is pausing the mail size increases. Some of these theories include removing GMail from Beta, unlimited storage to be released in the form of GDrive, and possibly seeing it as a good day to re-evaluate the storage situation.
My guess is that on April 1, 2007, GMail will no longer be in Beta and that would mean that anyone, anywhere in the world would be able to sign up for an account without needing an invitation or needing a cellphone for an invitation code.
How does ZDNet know that GMail will stop at 2835MB? Cybernet News had e-mailed the ZDNet author and the author informed Cybernet that if you set your computer clock to anything past April 1, 2007, the counter will stop at 2835MB. This may possibly be fixed by then or that may truly be when they plan to take GMail out of Beta.