Friend list: It would be great if we can see who all have added me as a friend.
Motto in profile: I really like reading mottoes of users in topcoder, Introducing it to codeforces will be fun.
Country-wise Standings: I think that would be useful
Activity log of friends: basically contains timeline of friends submissions, comments, blog etc
Filtering comment section: Sometimes we only look for meaningful comments in blog.. Only seeing comments of red user or something like user having rating > 1900 would be useful
what do you guys think of these features?