It would be nice to have a report showing how many up and downvotes you got in each tag. For example:
java: 134 upvotes, 10 downvotes perl: 100 upvotes, 8 downvotes hibernate: 50 upvotes, 4 downvotes
It will be easy for somebody or yourself to quickly check what you're good at and your main areas of interest.
You will be able to check how close you are of getting a tag badge ("Earned N votes for answers in the X tag").
The report could filter out the tags where you got less than, say, 50 votes.