No! No! They can't remake this. That would be a disaster. Why improve on something that doesn't need improving? Besides, no-one could play Hutter/Harker's part like Gustav von Wangenheim.
To be honest, I didn't like Gustav's performance. The extent that he overacted to made me cringe.
However I don't think Johnny Depp would be a good choice for the character. Depp usually portrays humorous characters, I don't think I'd be able to take him seriously in the part of Hutter.
Also, if they did make another remake, I would want them to keep the original character names, not using the Stoker names like in Phantom of the Night.
German Expressionism is as the name suggests "expressionist". Actors of that period over-acted and everyday life was exaggerated. That's what it was all about. Also, with it being a silent film, it's hard to get across what is going on, so expressions need to show it. Gustav's performance is supposed to be humorous, to contrast with the serious performance of Max Schreck as Orlok. And you can't just blame Gustav for over-acting. What about Greta Schroeder and Alexander Granach?
The only reason remakes happen (of course there are exceptions now and then, however this would not be one) is MONEY. To remake this would only be an insult to it. (Though I think that surely someone must be able to do something with a computer about the day-for-night bits...)
The last remake (Klaus Kinski as Orlock) was horrible. You cannot get this atmosphere like in the original movie. And, by the way: we have enough "remakes" of good movies, they have destroyed the originals ...
Doug Jones/John Malkovich as Orlok Cillian Murphy/Eddie Redmayne as Hutter Natalie Portman/Jenna Coleman as Ellen (maybe she's too old, ok) Christian Bale as Harding Richard Wilson as Bulwer Warwick Davis as Knock