Google have now enabled the ability for signing into multiple Gmail accounts on your mobile. Before hand if you used the browser on your phone you could only sign into one Gmail account which obviously produces problems for people like me who have two email accounts, personal and business.
Two other features being added are mobile-specific signature and vaction auto-responder.
Mobile specific signature, as the name suggests, enables you to have a custom signature for when you send emails from your phone.
Vacation auto-responder enables you to set automatic responses to emails, which before, could only be done on a computer.