The SERP did link to the correct (canonical target) domain. If the canonical tag is on domain1.com/product-a, the SERP was correctly pointed at domain2.com/product-a.
Because the page on Domain 1 is supposed to be de-indexed, I was expecting not to see the page at all. This is my first crack at cross domain canonicals. It's an interesting way for Google to handle it.
BTW, from a rankings perspective, the cross domain canonicals were extremely productive. Domain #2 got some huge rankings increases.
I've been tracking the results closely. I should publish the results when I get a chance. The most important result is that the keywords (+/-700) associated with the canonicals improved by an average of 22 positions over the higher position prior to the canonicals being implemented.
What I mean by that is for a keyword (ex: "widgets"), Domain 1 was Ranked 46, and Domain 2 was ranked 57, our average improvement was to position 24, which is 22 positions better than the higher ranked domain (in this case, Domain 1).
Rankings improvements for keywords already on page 1 or Page 2 increased by an average of 2.5 positions over the better ranked domain.
What was really cool was that when we canonicaled in the "wrong" direction, where the keyword ranked higher on the domain that was getting the canonical tag, the results were indistinguishable from the results where we canonicaled in the "correct" direction.
So, in this case, if a keyword ranked higher on domain1.com, and we canonicaled to domain2.com, the average ranking increases (from the higher ranking position) were almost identical to using canonicals in the "correct" direction (from the lower ranking position).
These are both ecommerce sites with DAs of +/-40.
What was also interesting is that Google accepted the canonicals in cases where our product descriptions were markedly different.