2K is nearly the same resolution as 1080p (2K=2048x1152 and 1080p=1920x1080) and it is the resolution most digital projectors in cinemas use, so the resolution shouldn't be a problem at all.

I recently saw a 2K digital projection of the new American Pie and it was beautiful, because if it wasn't for the digital subtitles, I would have believed it was actually film (I was a bit disappointed that the BD of it didn't quite live up to the same standard) and I remember thinking the same when I saw the 7th Harry Potter film.

In those cases, when you think about it, they use 35mm to shoot it and then use a digital intermediate which is then either losslessly encoded and projected directly or copied to film, which can only degrade the quality because with high quality digital projection it will look like film anyway because it was originally shot on film and copied to film, it will simply be one or two generations removed from the oneg. This is a similar situation - I bet lot of people wouldn't recognize it for not being film if the scanning, cleanup, encoding and projection were of high enough quality.