I gotta agree with the poster above. I've watched the anime multiple times, and if the manga is going to follow the exact same plot, well... Nonetheless, I'm sure diehard Nanoha fans will love this :P
I'm that diehard Nanoha fan XD I rewatch the anime and reread the manga from time to time, and every format has some cool unique thing in them that makes me love them. I am looking forward to what is going to make this adaption special :)