Extending the current tagging functionality from just users to other tasks and/or issues would help when dealing with work spread out across the organization.
Something as simple as "Check tasks @92515 for details and tasks @92456 for previous work" or "Is this a duplicate of task @93456?" where the @92515, @92456, and @92515 become links to the tagged items.
Right now the only way to do this is by copying and pasting the entire URL into the update box, which is extra steps and can clutter up the update.
