Uncompressed would definitely be nice, but that becomes an issue of replacing BluRay with a new format that can handle it.
I'm slightly confused when it comes to 2k, because it seems that the official resolution of it is 2048x1556, which is another million pixels when used in its entirety, but is a 4:3 format
I've always wondered why BluRay opted for hardcoded black bars rather than anamorphic... seems anamorphic full 2k might be a worthy step up in HD quality...