Rumors that I had been hearing prior to E3, by people who should know these things, were pretty much centered on the PS4's lack of backward compatibility. Sony had already stated that PS3 titles and PSN content would not be accessible on the PS4... And that would include Home also.
But, at the E3 press conference, they touched on the cloud service that is being developed as a relatively new factor. This would give the PS4 backward compatibility, and quite possibly enable Home to run also. But my impression was that the idea was still new and they probably simply don't know yet.
And oh yes, part of that rumor was a new virtual community build for the PS4, but something changed and it's no surprise that Sony had no information to share.
Well maybe come the PS4 we will know if it will be on the system or not and if not then we know we may have up to 2 yrs or so before it shuts down, just my guess as i also speculate the future of Home. I myself am not worried that Sony hasnt let us know the timeline of Home if it indeed has one at this moment, maybe they just want to see how many Users will complain about it but either way my PS4 will be for gaming for the most part as it is being promoted as along with the music unlimited app...