Since I've experiencing issues on this as well, I've been thinking that referencing i.e. project.version in a parent pom (to the parent's version) should be possible.
I might not see a certain UC or already implemented behaviour, but wouldn't this be possible (and still be backwards compatible) by adding one of two behaviours:
1. A way to specify properties that are resolved to the correct version (from the pom that they're in) either at install time or at the time the effective pom is generated. A proposal on this option would be to use i.e. #
or maybe $[property]
I think that this might even be possible in a Maven plugin, but there will be a problem with backing up the pom first then as well. If there's a way to hook into the effective pom generation it can be done cleanly though without touching the pom on disk.
2. A way to specify a certain parent in the hierarchy, though this would require a model change. It would then be possible to request a certain parent, i.e. by doing $
Personally I like #1 the most, though #2 is probably the most powerful. Both will of course require a substantial amount of work, but I expect that #2 will require a lot more than #1.
ps. just wondering: are votes counted together from all related issues? If so I might vote on them all