Believe it or not, this is already in development for 0.3
The biggest reason why it's not in yet is for security reasons. That is what's taking me so long on it. We plan to use an asymmetric 4096-bit private/public key RSA signature to validate updates, and the public key will be built into the updater. If we can get the signature verification to work, this will be a piece of cake.
I'm sorry for now that you have to update manually, but hopefully soon this will be a thing of the past -- we just wanted to make sure everything's secure before venturing on a task like this.
Thanks for the request, though.