I think, and I'm inclined to believe anyone that has seen him in Friday Night Lights will agree, that Jordan is a great choice for the role. It's also a large shift - looks like Johnny and Sue will (like everyone else) will be much younger this time around, and someone's going to be adopted, or both. This opens up the possibility (I.e. likelihood) of a foster parent situation, where both characters will feel 'alienated', have only ever had each other, etc. And while fans would hope and pray Fox has learned their lesson, one can't help but foresee the villain having some sort of tie to the kids' tough upbringing. Toss in studio desire for 'grit', 'groundedness', and what appears to be the need to redefine/modernize "Family" (not to mention a rushed move to keep film rights) and it just appears to be a reboot for reboots sake.
I'm all for a reimagining, and I totally get and am intrigued by 'Family' being used as an ideal, and not some strict notion of the word that limits plot points and story telling. But speaking of story telling, too much focus on said family and said grit/emotion comes at the expense of the science fiction aspect which is a necessary part of the equation to make a Fantastic Four movie effective.