I think the future of local TV stations is going to rely on the "Virtual Channels" in 2 or 3 years time. Once the dust clears from the DTV conversion, I think in each market any TV station will be able to put itself on any channel it desires. I think once everything is said and done, in the San Diego market, over-the-air stations will be on the same "virtual" channels as they we're on cable systems. KSWB 69 (or whatever calls they'll become) will be on 5, XETV (The CW) will be on it's usual position on 6, KNSD will be on 7, KFMB will be at their usual position on 8, KUSI will be on 9, KGTV will be on their usual position on 10, KPBS will be on 11, XEWT (albeit Analog) will be on 12, and XHDTV (MyNetworkTV) will be on 13...
...And if you live in an area where you get LA stations in the SD market, you'll probably end up with 2 channel 5's, 2 channel 7's, and 2 channel 9s. Hopefully these manufacturers of DTV boxes will be able to have these stations distiguished from one another, by call letters.