Let's say I've got a domain with 10,000 backlinks, if I 301 it to another domain, will the PR/'link goodness' ooze over to the new domain? And if so, what's to stop me changing the 301 every few months to inject some life into a new site? I know this is probably a stupid question with an equally stupid answer.
Nope..What would happen is that your older domain would slip down in SERP rankings and eventually get de-indexed leaving your other site without any backlinks. 301 re-direct is great for the short run but over a period of time, you need to build up backlinks for it as G would stop sending traffic to the older site.
301 means 'permanent redirect', so in my understanding, the search engine understands that it is to drop all the pages of that site, and transfer the 'goodness', as you put it, to the new site. permanently. and i think that, unless the site structure of the 2 sites is identical, only the home page backlinks would count.
Yeah, the permanent redirection will also "redirect" PR, backlinks, etc. But if your site is healthy I don't see the point in redirecting.