This is related to the Neverland post, but slightly different.
I think that SL is great, but without "attractions" like these and places to go everything is ephemeral, lasting only as long as the players pay to hold it in existence. People tend to gravitate towards the mundane and base side of things without a constructive direction to proceed in.
It would be nice if players could collaborate on mass projects that would then be maintained as part of the permananent LindenLand landscape, perhaps cities that once built remained rent free...infrastructure for the game's growth.
I think SL would do well by zoning: clusters of co-located sims to match separate and facilitate differing genres.
One of the prime methods of drawing income for LL is land, but people want content to make them want the land. SL could draw a lot more people simply with the content creation it already has ALONG with a consistent and enforced genre zones.
The current Linden Land would occupy the center of the "multiverse" with peripheral sim clusters dedicated to genres such as western, fantasy and science fiction/future. Players could purchase and buy land in these zones like the rest, but there would be thematic restrictions.