WordPress.com only seems to allow for annual payment of Upgrades. Having seen many come into the Forum after having lost the billing email or what ever and had their Upgrade go away. It would be an improvement if WordPress.com would allow the Upgrades to be paid into the future a few years.
I have friends that have their Domains out to 10 years. I have mine at I think two years. As someone that has lost or forgot about the billing emails, having the ability to pay forward would offer piece of mind and prevent service interruptions.
thanks