I used to have the NHL Network via my satellite provider, but I ended up dropping it, because all the games I really wanted to watch were all being televised already locally to through other channels. Having every game available was nuts, since in my case, all of my team's games are on TV, either in English or in French.
Up here we don't have any MLB packages, so I pay for the MLB.TV packages, which allows me to watch every game I want, except the Blue Jays, who have most games on TSN or Roger's Sports Net, which means I can see pretty much any game I want.
If my satellite provider offered a MLB package at something close to the MLB.TV Mosaic prices, you can bet I would have that over the MLB.TV, and even if the price was a bit higher, I would get it.