I don't think most of the people that replied really cared to read the original post. He's NOT looking to upgrade to full frame.
That being said, I would highly recommend the 7D, having spent the last three years shooting with it exclusively. To be fair, the new t4i is supposed to have one more stop of ISO usability than the 7D, and will benefit from the new Digic 5 processor in noise reduction, mostly in the in-camera processing when your shooting JPEG. They're both great cameras. The 7D is a lot more sturdy and just feels better in your hands. After shooting with a 7D, a Rebel will feel more like a toy. If you don't need that toughness, weather sealing, and 8fps, look into the t4i, which should give you equal, if not better, ISO noise quality.
I just got a 5D Mark III, and I can't bring myself to part with my 7D. With the price of the 7D right now, you can't go wrong if that's your camera of choice for upgrade. The quality is head and shoulders above the 30D, and I'm sure you would be pleased.
If you're not looking to upgrade to FF, don't listen to all these guys going on about how much better it is. There's ALWAYS something better out there for lots more money. You need to look at your needs and your price range and decide what camera is best for you. The 7D will make an awesome upgrade in IQ and ISO quality. There are other options (60D, t4i, etc.) that you ought to look at also when choosing a crop body, but considering that you take sports photos, the 8 frames per second on the 7D might be a deciding factor of what would best fit your shooting needs. Hope this helps.