Well, do they? If a domain expires now, gets deleted, and it is PR3... if someone buys it in, say, 3 years, will it still have the same PR?
It might happen. I've seen some people buying expired domains which turns out to have some PR. However, it might lose its PR if you don't start getting new backlinks asap since most of the old ones might not longer exist.
For sure, if the domain is no longer live, it will lose the pr pretty fast! Regardless of the backlinks, a dead domain is not going to keep any pr.
Probably not. As the backlinks linking the domain is the main factors determining the PR, the PR will not remain the same, unless the backlinks are still there.
Repeat...if the domain is not used with content, it will lose page rank. REgardless of the number of backlinks.
ofcourse, as everyone said, the domain pr will lost if the domain gets down for a period of time and it's pr depends on the number of backlinks it has.
In my experience no. If its down for a period of time or you change the content/focus of the site then you probably will lose the PR.