The apps here (see below) don't look very businessy, and while the demographic I'm targeting isn't perhaps quite the same as existing summary sites, I don't think it overlaps a great deal with the lolcats type users, either. Are there "serious" facebook apps?
It isn't surprising that FB apps are not very serious, since FB is in its formative stages as a "real" website (one that is used for serious things, for arbitrary values of serious). I think that if facebook keeps growing like it is now, we will see the introduction of serious apps that in turn will attract more users, etc etc. Remember, 10 years ago no-one thought the internet will be used for serious things.
http://news.com.com/2300-1026_3-6191391-9.html?tag=ne.gall.pg