Shoutbox

This can't be a Plus! Live thing, since the plugins that provide the Now Playing information are actually plugins for the media player in question. Anything attached to Plus! merely listen for the media player plugins to broadcast the information.
So basically, you need a plugin for your media player that can read ID3v2 tags. From the sounds of it, you use Winamp, and there isn't a suitable plugin yet. It may be worth contacting the author of one of the plugins that does as least some ID3v2, and seeing if they'll add the rest.