Different avatars like LiveJournal

You might have seen this neat little feature on LiveJournal:

Some users like to use different avatars for certain posts (for example, if they’re happy, they’ll use a happy icon for that post; if they’re irate, they’ll use a mad icon; etc.), and if a specific avatar isn’t assigned, then a default one shows up. I think this is neat–I enjoy simple little blogging features like this.

I was wondering if something like this is in the works for a future version of WP?

(Apologies if something like this has already been posted; I searched for “avatar” in the forum and found topics related to Gravatar and “how to insert an avatar”.)