Gilgamesh has never really been developed much as a character but he is supposed to be even older than Herc so I can see why he's be bored and I can see the two of them having a good partnership if handled correctly.
I like Herc's classic Kirby-designed costume and the subsequent costumes based on the original design, too. I'm not a big fan of all the 90's-style pouches or he bun Herc appears to have his hair in but other than those things this new look isn't too bad.
I hope the new stories garner Herc the respect he truly deserves by telling good/great stories and by showcasing how truly strong, skilled and courageous he is. I'm not sure what Gilgamesh's role will be. (What is his role?) I like Gilgamesh, though, and think it makes sense to have another immortal appear alongside Hercules.
This is just awesome news all around! Pak and Van Lente's run was amazing and all of Bob Layton's were masterpieces. I just hope that Dan Abnett really establishes Hercules as the true powerhouse he is to rival Hulk and Thor.
Also I'm very interested as it sounds like Abnett is going to exploring his actual fighting skills which will be cool to see.