We need to resolve artifact coordinates in the POM, including project coordinate, dependencies, plugins, reports, etc. but NOT plugin configuration sections. These coordinates need to be resolved prior to plugins like GPG being executed, and prior to install/deploy steps, to ensure that signatures and derivatives (shade plugin output, for instance), along with installed and deployed copies, contain resolved values.
We attempted this for version expressions in 2.1.0, but this had several problems, including not being in place for plugin executions, and resolving version expressions within plugin configurations. When we tried to remedy this in 2.2.0, a bunch of more subtle issues sprang up, which are described in the link at the top of this description. In short, we can't really solve this adequately in 2.2.0 without performing major surgery, and even then I'm not sure it'd work. We need to consider this as a design requirement for Maven 3.x, where we can design it into the system instead of trying to retrofit...