Ready for my rant? Spoilers ahead...
I've been saying it since I begun reading the Mighty Thor, Matt Fraction has no business writing the Silver Surfer or Galactus. First he puts Odin on near equal footing with Galactus and totally misses the character of the Silver Surfer (and Thor I might add), but now he has done some great damage to the character that I originally thought was material in a non-canon book. Apparently, it is not as it states that this book takes place before Fear Itself (but who knows where in the Surfer's timeline).
So if you haven't read Mighty Thor #6, Thor and the Silver Surfer have discontinued their battle for whatever reason and are trying to stop Galactus from eating the Worldheart of the Tree of Life. Who knows why the Surfer changed his mind, but let's just roll with it. Turns out that Loki hid the Worldheart and now they can't find it. So you think they would just leave right? Nope.
The Silver Surfer decides to stay on Earth to guard the seed. Galactus makes Pastor Mike from Broxton, Oklahoma his new herald, the Surfer is given a human form and a limitation - the further from Earth he travels, the weaker he becomes. The entire character of the Silver Surfer (and Fraction's own creation, Pastor Mike), is thrown to the side.
Why would the Silver Surfer, who knows the great burden and sacrifice of becoming a herald of Galactus, offer the position to another person? Why all of the sudden does the Silver Surfer care about one life over that of cosmic consonance and his great duty to the structure of the universe? Why would he think that this amateur man of God could do what he couldn't and find planets for Galactus that wouldn't cost a single life? Why would Pastor Mike betray his God in exchange for the burden of providing worlds for a cosmic being to destroy? Why would Pastor Mike think by leaving Earth and being a herald of Galactus that Broxton would be safe?
If you add these questions to questions like, why couldn't Galactus simply destroy Odin and all the Asgardian Gods with the snap of his fingers and take the Worldheart in the first place, and you basically have an open ended story that's only purpose was to change a non-title character. Really, all we got out of this for the main character was a small bond between Thor and Loki. Otherwise, it just kind of crapped all over the Surfer and Galactus.
I supposed the "tethering" of the Surfer to Earth was done for the upcoming Defenders book and might explain why the Surfer does not appear in the new Annihilators book (disappointing). I have to say, I finally understand why most fans dislike Matt Fraction. Stick to what you are good at Matt, and it isn't Thor or the Silver Surfer.