I think the networks still enjoy some buying power when it comes to production and talent efforts, but you're right...it's in it's decline.
The post Friends/Frasier world is looking glum for networks and once other mainstays go (like Raymond) with limited replacement prospects other than reality crapola...its' all downhill.
But the formula is changing to survive. Reality TV is cheap compared to SuperStar salaries. And if the ratings are as good...same income from advertisers. Which is really where everything is determined. What do advertisers consider the best value for the money? And they're still eating up the networks (for now) since it's the best national reach going.
Granted there are more targeted ways to reach 45 year old virgins if that's your market (you mentioned Sci-Fi), but the networks still own the broad spectrum of America. And just think of the new revenues syndicated reruns have produced from cable!
Soaps and game shows had a one day shelf life for networks for years. Now they sell them to cable channels.
And like I asked in U2U, are you sure I don't know you from somewhere?



And it didn't stop there. Soon, there were Cable TV channels who had shows that
could outperform Network TV in every way the networks could measure (demographics, ratings, merchandise, etc.)... And, here and now, it appears that
the financial grim reaper is around the corner for the Networks...