There is an interesting WebmasterWorld thread where a webmaster said he did a site move to a new domain and the PageRank funneled within days. Specifically, he had a discussion forum and store on a .com, he bought a .net recently and moved the forum to the .net.
The .com domain kept the PageRank, which makes sense but the .net picked up PageRank within over a "few days" time. Normally, Google PageRank does not flow that fast, especially as shown in the Google Toolbar.
Every single reply in the WebmasterWorld thread is skeptical. But every possible explanation, so far, has been shot down by the webmaster who is reporting this. Keep in mind, the webmaster finds this to be odd as well.
Of course, there can be factors we are not considering yet and maybe it is just the PageRank is being assigned to the domain as temporary or artificial PageRank?
But this is an interesting case, nevertheless.
Forum discussion at WebmasterWorld.
Note: This post was scheduled to be automatically posted today.