I learned this news yesterday. My immediate thought was they don't need to reboot concept, just reintroduce the character and his world back into a new film. Period. My only other wish is that they embrace the era of the film more. Retro is very cool, and I think it'd help the film stand out on its own more because, let's face it, Captain America has already just played that card. Add to that the fact that the Rocketeer is sort of Captain America's golden oldies charm mixed with Iron Man's flying spirit suggests an even stronger need to create its own identity so it doesn't get labeled a rip-off by audiences who don't know about the previous film.
My favorable opinion of the original film is colored by the fact that I was a fan of the comic book, discovering it years before the movie came out. Casting Bill Campbell as the Rocketeer/Cliff Secord was an unbelievable coup as he looked exactly like how the character appeared in the books! An unknown then, I have my doubts that Disney will be able to strike lightning like that again a second time around. Fingers crossed that (a) this ultimately gets green lit with a great script and (b) Disney delivers!