SAI is reporting that MLB’s At Bat application ($9.99 iTunes Link) will start streaming full live baseball games to iPhones. The service is set to go live this week, possibly in conjunction with the iPhone 3G S launch. You’ll need to update your copy of MLB’s application, and of course to do that, you’ll need to be running the 3.0 software. They also note that the service will work over 3G, though this hasn’t been verified. This would be a pretty big blow to apps like Sling who have been relegated to working over Wifi only. If it does stream over 3G, we’d expect the quality to degrade, much like Youtube.
MLB also sells a separate app for baseball gameplay (thanks commenters).