So, we have our writers - Jeff Kaplan and Ian Springer. They are supposedly not just working on F4, but future F4 installments as well. I normally wouldn't get too worried about this stuff, but with a property that desperately needs to be done right, I looked into their credits and they've done... almost nothing. That's not a bad thing per say. Maybe they just had a really good pitch and script for the franchise and Marvel decided to go with them based on that.
Deadline had this to say on them:
"As for Kaplan and Springer, while new to the scene, the writing duo is one of the hotter screenwriter teams in town, having sold a number of specs in the past year. One of those high-profile projects is the Warner Bros. comedy Disaster Wedding, which recently landed Palm Springs helmer Max Barbakow to direct."
It will be very interesting to see how this turns out, but we've seen Feige pluck up and coming duos like this before, namely with the Russo Brothers and that couldn't have worked out better.