Yes, it does support hard drives bigger than 2 GB. _Long_ time ago the ext2 file system implementation could not handle _partitions_ larger than circa 2 GB because the file system was implemented using mmap (cool is it not?). That restriction would not have been a problem if the operating system had been ported to 64-bit architectures.
Hurd is working --- its biggest problems are stability and driver support. It is a beautiful system that has little value for normal users as Linux is more stable and has better drivers. The beauty of writing file systems, network stacks etc in user space is amazing. So is the possibility for the _normal_ user to create their own file systems, in any language, using any libraries and mount them without root access.