It would be nice to be able to get a pending flag count that doesn't include flags you've already handled.
Consider the screenshot below, where I have selected the "invalid flags" category. Since I've already processed all of those entries, I get the "show posts you've already flagged" link on the left. But the count on the right ("14 x invalid flags") doesn't reflect that fact.
Moreover, the overall count (550) doesn't reflect that I've processed about 80 of those flags.
What I imagine is a sidebar like this:
The "processed, pending action" flags are the posts that I have already handled, but that have not yet been handled by a diamond mod (or that haven't achieved enough flags to be automatically handled).
Those flags would not be included in the overall total, but are still easily accessible.