JQL function to see if a fixVersion has a release date defined (EMPTY)

When using the agile functionality (Greenhopper) it is common to have versions for one or more backlogs which do not normally have a release date assigned to them. I have written up a small example below and will attach a screenshot of a current project.

• Product Backlog [No Date]
  • Approved Backlog [No Date]
  • Wishlist [No Date]

• Sprint [Release Date]
  • Iteration [Release Date]
  • Iteration [Release Date]

When using a JQL function like earliestUnreleasedVersion() it pulls back the "Product Backlog" in my example. What I would like is to be able to either set a parameter in the current JQL function or add a new JQL function to limit it down where dates are defined. Examples would include:

earliestUnreleasedVersion(PROJECT,hasReleaseDate)

OR

fixVersion in earliestUnreleasedVersion(PROJECT) AND fixVersion in scheduledVersions()

OR

fixVersion in earliestScheduledUnreleasedVersion(PROJECT)

If one of these options are possible then when running a JQL query for wall boards or Greenhopper rapid boards it would pull the earliest version with a release date, removing any problems with Product Backlogs.

NOTE: I have tried putting the release date way out in the future, but then the backlogs sort at the bottom of the lists. With the product owners being the least failure with JIRA, they tend to loose the backogs if they are not at the top of the versions in the planning board.

Similar functionality was requested in JRA-22549. I have also spent some time looking at the Versions Functions of the JQL Tricks Plugin, but it does not have the functionality requested.