I have an idea for a 'frequently updated' playlist.
All you do is create a bunch of smart playlists with your favorite artists - one for each artist.
Set the criteria to 'match all' and also include a line of 'last played' and 'is not in' and 'the last 7 days' and limit it to 5 songs, sort by random and 'live updating'.
That way, after you have created a smart playlist for each of your favorite artists, THEN you create yet another smart playlist which will be based on All the other small smart playlists you just created and call it 'frequently updated'. Match 'any' of the rules and sort by 'random' (if you're brave) or by 'genre' if you're not so brave. You can make it limited to 25 or so songs.