The only thing that bugs me about this, is the fact that there's also this promising new project of several teams going to work together to create all of the provinces in the default Tamriel worldspace, connecting everything. It would be in direct conflict with this Skyrim enlargement mod, while both projects have a chance of becoming a standard to make new mods on. Such a split is a real shame in my opinion.
I don't think it's possible to merge these two projects, since it would mean forcing the province-teams to build everything at a 2x scale as well, and most of them probably don't want that. If I had to choose between them, I think the province project has more potential. Perhaps it's a better idea if the community focusses on creating one new standard for new mods to be build on, rather than two that would be in conflict with each other.
With new provinces, you'd literally have a blank slate, the only things holding you being lore. That's a lot of room to move in, and that seeming freedom will probably draw many more modders looking to work on something big. Most of them are going to burn out first, though, provided both us groups get up and running. Some people will thrive on the combination of freedom and lore restrictions, but many will either get tired of those restrictions or the project itself will conflict with lore, much like parts of Unique Landscapes did. There's also the fact that they're just covering more ground than we would be. Most of the people going to that project will want to go to whatever area they want to go to; I doubt they're all focusing on the same place to start, but please correct me if I'm wrong. Even if the team mostly stays together, it's going to go like Tamriel Rebuilt did. They'll lower their scope.
All of this ignores the conflicts they'll have about direction, and all of the new resources they'll need. There's the obvious large amount of new textures/meshes, and there's the fact that everyone seems to want fully voice acted this time around. Looking at this like a competition for users, we'd be able to boast a much smaller download in comparison, a comfortable place for modders to build, much more completion in general, and they mostly wouldn't have voice acting which would deter some users.
But the way I see it is, there's nothing wrong with two installs.
