
I see only a few problems, such as using URL'd images as textures, could possibly add an object purely for image URL's. Inapporpiate images, wouldn't think many people would do that. And connection speed issues depending on update speeds, amount of updates and objects - but since SL is directed towards people with broadband I wouldn't think that would be an issue.
I think this would be a nice feature for things like TV systems, could offer people things to place on their TV's and make a profit off of advertising - both advertiser and advertisee. Just the issue of uploading textures fees and whatnot...not sure..
maki