We’re working very hard to solve the problem and we’re really sorry for the inconvenience. Those users in the US and UK who have enabled Gmail offline through Gmail Labs should be able to access their inbox, although they won’t be able to send or receive emails.
We’re posting updates to the Gmail Help Centre at http://mail.google.com/support/ and Google Apps users can visit the Google Apps help centre at www.google.com/support/a.
Thanks for bearing with us while we sort this out. We'll report back as we make progress.
Posted by Acacio Cruz, Gmail Site Reliability Manager