I like the idea of pre-loading. But there are a lot of gotchas involved with it. And I can't help but think of how I am with a build, little tweaks all the time. I like how things don't have a final state, they just have a current state.
That said, Qarl's suggestion about creative rendering is actually something that needs to be looked into. They already did it for loading avatars with the cloud. No matter how much pre-loading you try, you're never going to get away from downloading content. There definitely needs to be a creative visual interesting "loading" mechanism that encourages you to stay and watch as the world is revealed around you, and not just from a mass of gray.
This brings to mind all kinds of ways different applications and games and flash sites handle loading. One that comes to mind is Glitch when it's loading each street page. Perhaps instead of the teleport black screen of boring (which I turn off when I can in TPV's) maybe showcasing some info about the sim you're being transported to, including the place location picture. Like, the stuff that's in the search results and landmark/place info. Or even the map from above image. Just some idea of something to think about or look at while we're sitting here waiting. The screen could stay up longer to allow more of the world to load.
Fill the downtime with interesting things to look at or giving information and it makes it hard to leave. Just my $2L