Speilberg meant we (Lucas, Ford and I) are ready to take on this project and we are waiting for Paramount to shell out huge loads of Development money to hire writers to take some shots at it. And they have, some five writers and they all missed badly and it WAS like that since 2001. Honestly, you are correct there has been a lot of speculative talk but it was all BS until the Nathanson script came in "looking real good" last December.
Since then, Spielberg and Lucas have given him their rewrite notes, and have felt comfortable with the basic story and story elements, good enough for Paramount to put it on the front burner. The only piece missing (the actual business deal for them) was to get Speilberg's rubber-stamp gatekeeper, Universal suit ("The Island' anyone?) Stacy Snider of Universal, to come aboard Paramount so he could fund this project the way he wanted, negotiate his fees, etc and line up many more of his projects. If you noticed, once Stacy came aboard Paramount, this project all of a sudden, gained real gravitas. In any event, I am convinced it will take off once the budget is settled and you will hear a lot more about it, it's real, believe me because once the script meets final approval, pre-production follows.
And the script has been approved according to the Principals involved.