I like the others that have posted before me really wish Cain to return being the Juggernaut. Cain will most likely return to being the Juggernaut later on, hopefully not depowered this time around. In the mean time if they're going to have a new avatar for Cyttorak then I hope it's someone that can add more interesting aspects. Don't get me wrong the original Juggernaut was fine the way he is, but Colossus didn't really add anything except for metal skin (cosmetic change). I want the new avatar to have additional powers that will mesh with their new found super strength, and invulnerability.
Another thing I want to see is more Cyttorak. Outside of the old comics where he kidnapped Galactus, and his heralds along with Classic Doctor Strange, and banishing Colossus with a portion of the Phoenix Force he really doesn't have a lot of feats going for him. Would love to see more of what he can do, and where exactly he measures in the whole cosmic hierarchy.