For the purposes of this fictitious remake, let's suppose that the new film will also be set in 1932 Berlin. And so for the cast, perhaps a mixture of international and Hollywood...
Baron Felix von Geigern- David Bowie. Songwriter/Singer/Musician, but let's face it, Bowie has never made as much of a film career as his own great performances in the few films he has made would warrant. And the part of a Baron who has been forced to become a jewel thief in order to stay away from creditors, a man who hates what his life has led him to, who looks to a moody ballerina and a dying accountant to help give him some meaning to a meaningless existence... Bowie would nail this. Watch him as Pilate in "The Last Temptation of Christ" or in "The Hunger", or even as Tesla in "The Prestige" and see an actor who would rock in a part like the Baron.
Grusinskaya- Lena Olin. Ever since international audiences saw this Swedish actress in "The Unbearable Lightness of Being", there has been the expectation of exceptionally intelligent and emotionally mature performances in her characterizations. I can't think of anyone who could match frickin'* Garbo in one of her iconic roles (she even says "I vant to be alone" in this), than Lena Olin, an actress who finally forced to me watch "Alias" purely because she was on it. The part of the ballerina who is lonely, moody and difficult. Olin would go to town on this. The only thing would be that you would have to change the character from a prima ballerina to an ex-prima ballerina (or an Isadora Duncan type? Someone who went on dancing and giving performances into their later years?) in order to allow for Olin's age. I'm not trying to be ageist, but the reality of the dance world at that time would demand it. Even Garbo thought she would be too old to play the character.
Flaemmchen- Amy Adams. Is there anyone on the planet who doesn't know who Amy Adams is at this point? I mean, when is the media backlash going to start? Well, before it does, she should try to do more offbeat projects like playing an ambitious secretary/gold digger with a heart of gold, a part that originally drove the mighty Joan Crawford to even greater acclaim. Adams is both a good comic and dramatic actress (see "Junebug") and would be fine in this part.
Preysing- Philip Seymour Hoffman. The bullying industrialist who is Flaemmchen's boss and has brought her to the hotel for an affair with his secretary. Hoffman, who has played variations on "bully" since the beginning of his career, would own this. Yeah, that's right, I said "own". Seriously, an actor as good as he is, would bring more vulnerability to what is, in Wallace Beery's hands, a two-dimensional, German-accented monster. Preysing employs an accountant dying of some sort of thirties movie disease...
Otto Kringelein- Lee Evans. Kringelein, the dying accountant, was originally going to be played by Buster Keaton, before studio chief Irving Thalberg moved on to John Barrymore's brother Lionel. Now Lionel is really good (and a revelation to people who only know him as Mr. Potter in "It's A Wonderful Life"), but in thinking about this, there is something cool about having someone known for physical comedy playing this insignificant little mouse who becomes a big man by the end of the film. Evans is one of Britain's secret comedy weapons in the world of Hollywood (see "Funny Bones" to see how awesome this guy is... he upstages Jerry Lewis!) and would be on fi-yah in this part.
Dr. Otternschlag- Bruno Ganz. Well, this does take place in Germany, it'd be nice to have an actual German in the cast. Actually Ganz is Swiss-Italian, but he is an icon of German cinema including Wim Wenders' "The American Friend" and "Wings Of Desire", as well as playing Hitler in "Downfall". To play the drunken doctor who loudly proclaims at the beginning and end of the film the ironic line "People come... people go... nothing ever happens", one needs to be quite an actor to put over such an irony-as-theme piece of dialogue. Watch Ganz in some of the above. You'll see what I mean.
Director- Alan Rudolph. A film as big as this would need a director who can handle large casts, but, in this day and age, bring something new to what is, admittedly, a period piece. The first director who came to mind was Robert Altman. Well, Altman died a couple of years ago, so I moved onto a great, independent filmmaker who also happens to be one of Altman's proteges. Rudolph made two of my favorite films "Mrs. Parker and the Vicious Circle" and "Choose Me". The first is a great film about the collection of artists, writers and wits who comprised the Algonquin Round Table of the 20's and 30's. The second, while firmly grounded in the early eighties when it was made, is a still relevant, universal take on love and the masks we use when we do the communication dance of trying to find someone to love. Both show how qualified he would be to make this remake.
So, that's what I got.
Any better ideas?
*Swedish for "f'ing".