@KR Good point, you're right, it shouldn't require a sim viewer download, just the chance for the set login screen to display information about the sim you're set to login to.
I was getting a bit ahead of myself as I've suggested in the past the idea that instead of people going to Second Life, they could think of themselves going to Community x (where x is the name) running on Second Life technology, but I'm in danger of going off on a tangent here.