Historically one of the biggest problems that Web site owners face when moving onto different domains, or even changing directories, causing updated URLs for pages already ranked in search engines. SEO experts have long recommended the use of 301 redirects versus 302 style redirects, and then more recently Google launched the Canonical Tag which they created to be inclusive of the 301 "link-value-passing" functionality.
We have performed testing of the canonical tag and have attained good results in removing unwanted duplicates from the search engine results. We have typically audited the rankings for updates, but have not set up a "speed test" like Tony's. The cross-domain use of this tag is not something we have a lot of experience with, but according to limited implementation, Tony's study, ands other reviews of the tag's use from one root domain to another, the functionality is effective.
It was noted in the comments to Tony's post that his results were somewhat personalized, which I was thinking about as I read through the study. However, as pointed out in the responses, the newer domain does have rankings for the "SEO keyword research" even on non-personalized results. I am seeing only the new domain for the "business development opportunities" search results, although for both they actual rank is lower from my seat (4 and 7 respectively).
Hopefully more people with experience testing 301 redirects versus Canonical tags, especially across different root domains, will share their findings at Sphinn or Tony's blog.