Unfortunately, it will run only on PS3 as far as I know. Other than that Sony will not open it to community created content, only to certified content providers. Its centralized approach is also seen as a negative side.
So far only the good graphics and the good integraiton with the hardware platform sounds like an advantage compared to other virtual worlds.
It will be interesting to see what happens with PS3 Home now that Phil Harrison has resigned as President of SCE Worldwide Studios. Phil was one of the key individuals at Sony pushing for more casual/social-oriented play, and has expressed his frustration with Sony Japan's reluctance at engaging non-hardcore gamers.
As others have pointed out, Home is not (at present) an open community where anyone can create (3D) content, but more of a social networking virtual world which allows/compels PSN developers to create additional interfaces and content for their games. I'm a bit concerned about the additional overhead this creates for developers outside of their core titles, but I've been informed that SCE will be creating Home content, at least for WWS titles.
Yep, I'm all ready for it (I hope). Although, I'm curious about how well it will be received by the two distinct genres in v.worlds sandbox/social, as well as the general perception of it by gamers. Hopefully, Home will have extraordinary integration with various game titles, but I fear it will come out the gates soft and take a very long time to grow. Sony is somewhat notorious for that.
I almost wrote off the PS3, but piece by piece, little things have impressed me with as I've owned one over time.
It certainly looks interesting enough to try. We need more of these types of services on consoles if the console is to maintain a "home network" type of platform that the developers are hoping to introduce. As usual, I need to try this out myself to be sure it is something worth having long-term, as I have also heard good and bad about it.