We are just starting to use the ideas portal - we have officially rolled it out to all of our salespeople.
Right now we can link ideas to features, but we would also like to be able to create relationships between ideas.
Why is it useful?
Who would benefit?
Product Managers responsible for reviewing, following up, and implementing the ideas would benefit from this idea.
How would it work?
The Action menu for an idea would include 'Link idea to another idea'.
Options for relationships would be the same as for features - relates to, depends on, duplicates, contains, impacts, blocks, and their opposite relationships (is a dependency of, etc.)
|Release time frame|
This is possible today. From the Actions menu on any idea, you can link the Idea to another record (which includes any idea, initiative, release, release phase or feature).
You can read more about it here: http://blog.aha.io/universal-dependencies/