I was throwing together a Techmeme for sports, and while compiling a list of sources, I ran into this same problem. As far as I know, there isn't enough sports content out there, which makes sense if you think about it.
The issue with sports is that there's a ton of re-blogged information, so the issue is finding the original source algorithmically.
What you should do, if you're serious, is rank articles by the length. It's a brute force measure, and it won't be accurate, but it's a good place to start.
Then, figure out a way for people do isolate it to their teams. The Southern Illinoisan newspaper is probably going to be the best source for news about the SIU Salukis, but I never remember to go there, so I get excited when I see a snippet on ESPN.com. You find a way to get me the best news about my Cubs, Salukis, White Sox, Bulls, Illini, Bears, Fire, Arsenal, Blackhawks, and so forth down my ladder and you'll mint money.