I'm all for creating a better solution for short urls, rev=canonical is not a good option.
The proposal mixes alternative urls with the idea of a canonical url. Besides being damn confusing (remembering the difference between rel and rev), it opens up security issues. Moreover, the 'rev' attribute is not included in HTML 5, making this proposal obsolete before it even starts.
I've written up a longer explanation of these problems on my blog for anyone interested:
The proposal mixes alternative urls with the idea of a canonical url. Besides being damn confusing (remembering the difference between rel and rev), it opens up security issues. Moreover, the 'rev' attribute is not included in HTML 5, making this proposal obsolete before it even starts.
I've written up a longer explanation of these problems on my blog for anyone interested:
http://cubiclemuses.com/cm/articles/2009/04/12/short-and-can...