I'm probably going to be the only one to say that, given Tsukihime's melancholy feel, I'm content to let Satsuki remain a tragic heroine, and don't really care if she gets her own route. Basically, what I want would be:
* The expected better production values on the art
* As above, but for the music, though the melancholy classical of the original would be very much preferable to the style of the soundtrack of Fate/Stay Night, given the difference in feel of the two stories.
* Voices would be nice, I'd definitely prefer the Melty Blood cast to the anime's one. Anyone who watches subbed anime will know that voices, even in a language they don't understand carry a huge amount of character.
* A lot of people have said no H-scenes, but honestly, I felt that Tsukihime earned them. I felt they worked in what was decidedly an adult game anyway, and that they contributed to the storyline. If they could be written better, that'd be just swell, but they weren't there as anything other than necessary, logical character development combined with a little harmless fan service. Obviously, an option to skip them or replace them with a non-H equivalent would be appreciated, as this means people who want them get what they want and people who DON'T want them get what they want.
* Lastly, animated stuff. This is a chance to redo not just Tsukihime, but also the anime. We've all said that the Shiki/Arcueid vs Nero Chaos would be cool, but I am excited at the idea of a proper, well done (the idea of ufotable doing this is almost erotic to me) version of the "This is what it means to kill something" speech - the thing the anime should be most condemned for leaving out. We're never going to get a five-route anime, and it seems a terrible shame to have those fights go left to the imagination. That said, avoiding H-anime scenes would be nice - that WOULD be gratuitous, you can't really explain that as "like a sex scene in a book, but with the necessary pictures".