We are thinking of giving up satellite for Netflix. One of the reasons is that most of the channels are now so awash in commercials that it isn't worth the effort--and on some channels, the number of commercials become so obnoxious towards the climax of the movie that you start to lose the plot.
Another reason is that most of the channels really aren't worth watching. Yes, there are 250+ channels on Dish, but it seems like 60 of them are sports (which we don't watch), 30 of them shopping channels (even less interest), 20 are "adult entertainment" (no thanks), and many of the rest aren't carrying anything we particularly find interesting. My guess is that 90% of what we watch is History Channel, History Channel International, Science Channel, National Geographic, Animal Planet (which is better than you might at first guess), and Fox News (although less so, as O'Reilly's ego has become even more obnoxious, and the actual news programs become even more entertainment focused than before). For $60 a month, the amount of valuable stuff is surprisingly small--and Netflix's $8.99 per month is very attractive.
Here's my biggest concern (which I can't seem to find answered on their website). We have an adequate Internet connection--about 800KB downstream--but if the Netflix streaming has to go directly from your computer out to the TV, with no way to save it locally, this isn't going to work for us. An 800KB stream is going to lose way too many frames to be watchable.