It's nice, but I don't think that the Steam version needs a remade intro. IMHO ASCII art is fine.
Maybe, but if the rest of the game isn't going to be in ASCII either, why not update this too and make it more polished and readable? Also, there's been some indication from Toady that he doesn't consider it to fit in with the graphical version (and in a way, I kind of agree):
Has there been any graphic work done to the intro cinematic? Are there any changes planned for the intro cinematic, either for this release or long term?
We haven't done anything with it, and I'm not sure if we'll keep some form of it for the graphics version or not. It no longer fits, exactly, but we haven't made a decision.
So there's a possibility that if it's not updated somehow, it's not going to be used (at least not by default, which would be a shame, compared to being updated).
DF is a tile based game as is, so imagine the intro will be using pieces of art from within the game to be friendly to ASCII mode playability &/or will be run introless by default since that's a option via steams command settings. Commonly go into properties -> launch settings and '-nointro' for other games.
I'm not sure what you mean by it being friendly to ASCII mode playability (like, obviously running in ASCII mode it would use the old intro, that goes without saying). Do you mean that bit near the start with the dwarves walking in and out of the big door?
It would have to be custom to some degree anyway, even if it does take inspiration from the ingame tileset, since for most of it, just taking the current intro and using the tile graphics in place of the ASCII characters would look like a weird mess I'd think.