From the Marvel press release:

Giant-Size Hulk #1 has sold out at Diamond as “Planet Hulk” and all things Hulk continue to sizzle among fandom.
J. Caleb Mozzocco of Newsarama says, “Marvel’s “Giant-Size” format is the perfect one for Hulk stories—a character this big demands a big book, and, at 74 full-color story pages, Giant-Size Hulk #1 certainly fits the bill…with some great Hulk stories.”
Brian Ewing of IGN.com calls it a “must have…looking at the entire package as a whole, it’s a no-brainer.”
Featuring two all-new stories by Peter David and Greg Pak, one a Hulk-Champions flashback and a Planet Hulk interlude, along with a reprint of the popular Hulk: The End by Peter David, Giant-Size Hulk #1 delivered great Hulk stories all in one mind-blowing issue.
Be sure to pick up the next issue of the Planet Hulk saga in Incredible Hulk #96 as the next act of the Jade Giant’s epic begins, continuting from the events seen in Giant-Size Hulk #1.
Fans should note that some copies may still be available at the retail level.