While blue is my favorite color, I will hold out on this one. Who knows, I may visit Best buy and see how the blue color appears.
While the one best buy sells, the front will be blue as well, which is nice. But as others have side, you can just buy the blue back cover on ebay for cheap and just slap it on your phone. Since I'm currently using a Samsung wireless charging cover, I'm hoping that Samsung will release a blue color of that as well.
Plus, it's possible that Samsung might come out with the S5 Prime~