Spontaneous Musings

Would agree. Time was the only things on during the summer were reruns and sports shows or game shows. I rarely watched tv during the summer months as a result or I used it to catch up on shows I'd missed.

Northern Exposure sort of changed all of that - when it premiered during the summer and took off. (Pretty sure it was Northern Exposure that set the trend, which was later followed by WB, UPN and Fox starting shows in summer to grab audiences before the big three networks got up and running.)
Cable also had a huge effect - actually I think may be the advent of Cable that changed it. And if you'll notice -about all the shows listed above are on Cable stations. USA, FX, Sci-Fi, and TNT have gotten in the habit of premiering new series over the summer months, when they are less likely to get lost. It wasn't that long ago that these stations only showed reruns of old series or movies or made-for tv movies or reality shows.
But now they are expanding into regular series, since it is cheaper to develop your own sometimes than paying for syndication rights. (Plus you get to receive the syndication revenues/DVD revenues...)

Cable really has changed the television landscape. If it weren't for HBO's The Sopranoes (a tv show that would never make it past the network censors) - we wouldn't have House, The Sheild, Rescue Me, and Nip/Tuck.
The cable channels can do more than the networks could traditionally do, and that changed things.

Then - computers arrived. People can download tv shows. So networks are in competition with foreign channels and distributors. They are in competition with computer file-sharing. They can also utilize this new medium or platform to sell their program or do what BSG did - provide episodes for it (websodes).

The new online platforms from pc's to i-pods and cell phones has changed everything. It's why I have the job I currently do. And it's why the writer's guild of america is about to go on strike - a disagreement over the amount the writers should receive for websodes and tv shows sold over itunes and the internet.

Technology is a scarey and wonderous thing...;-)