This one’s a shocker. Today the San Francisco Giants announced that they will be leaving their long-time TV flagship, KTVU-2, for KNTV-11, the Bay Area’s NBC affiliate. KTVU continues to have a small stake in the Giants, which seems, well, awkward.

The deal will run for three years, with the broadcast teams staying intact.

For the Giants, the move shouldn’t change things much. KNTV moved their transmitter to San Bruno Mountain a while back, so from an over-the-air standpoint they should cover much the same ground. On cable they’re on channel 3 instead of 2. And it looks like KNTV will help produce some additional magazine-style promotional content.

The move’s much more interesting for KTVU. KTVU has been riding high on FOX’s numerous hits such as 24, House, M.D., and American Idol. All three of those shows air on Monday and Tuesday nights, which are primetime conflict areas for KTVU vis-a-vis the Giants. Even though KTVU has KICU as a fall back when that type of conflict occurs, I’m certain they were contractually obligated not to preempt Giants games for anything else. Those hit shows may also have been better lead-ins for KTVU’s 10 p.m. newscast than Giants broadcasts. That’s saying a lot since Giants broadcasts trump every other non-NFL Bay Area sports franchise. So if you’re wondering if the A’s could somehow slide into Oakland-based KTVU’s schedule – fuhgetaboutit.

This move is even more telling for KNTV, whose parent network, NBC, has struggled since stalwarts such as Seinfeld, Friends, and Frazier retired. Obviously, NBC-owned KNTV needs a better lead-in to its newscasts than much of its lackluster programming. A look at last week’s Nielsens shows not a single NBC primetime telecast in the Top 20 list – which was somewhat skewed by the inclusion of all four World Series broadcasts. Bringing the Giants into the fold has to be a steadying influence, even if an even greater majority of Giants broadcasts will end up on FSN Bay Area. Note to NBC: Please don’t mess with the Thursday lineup. I’m tired of you guys killing Scrubs.

From a regional standpoint, I suppose this kind of move should give the Giants better ties to the South Bay, but ever since the ownership change KNTV has been working hard to remake their image as a Bay Area-first station, not a Silicon Valley station. However, both parties might get more Valley advertisers in the process, the same way various Valley companies advertise on Sharks radio broadcasts. The NBC-Telemundo partnership may become an integral part of the broadcasts, though I can’t yet say for certain how.

In the long run, the length of the contract allows the Giants to test out a new flagship while exploring other ventures. If the Giants wanted to launch a new regional cable network, they could easily do it starting in 2011. Many teams are moving a greater number of broadcasts to cable, and by the middle of the next decade viewers could face a situation in which no A’s or Giants games were delivered over-the-air. It’s a day late for Halloween, but it doesn’t make the future any less spooky.