There are many different ideas for blender, some easy ones that might take just a developer an hour or much harder ones that would need deeper rethinking of feature and weeks to implement.

I think it would help to be able to categorize ideas by either difficulty level, or estimated time of completion.

This could be added by the user submitting the idea and then eventually corrected by a developer (who might have a bettter understanding of a complexity of feature and code).
This also allows developers to search for short ideas if they only have a few hours to spare.