I agree, it wouldn't be the end, but it would be so COOL if he did sign with us now. Would save us a lot of time 
tp. If he signed with us now as-is (without a trade gutting the roster) we could be setting this team up for a dynasty where we are instantly a contender but have young guys with tons of potential (smart, brown, our future Brooklyn picks) who could be groomed to take the reigns eventually. That's what the 60s Celtics did as they passed the torch to hondo. That's what the 80s Celtics would have done with len bias. And eventually Reggie Lewis.
We could have a window of like 5 years of durant's prime and assuming we got some luck in the draft Durant could evolve into an old man role like Duncan as brad kept the team on top with new blood.
It would be amazing. Fun to dream.