TheOptimizationIdiot - 7:49 am on Feb 25, 2013 (gmt 0)
Do you believe having a canonical from each page to itself (fr will have a canonical to fr, es canonical to es etc) will cause duplication issues?
I doubt it will cause duplicate issues.
Once you say 'Page B is an alternate for Page A' and 'Page C is an alternate for Page A' you're also saying 'Page C is an alternate for Page B'. You don't even need to have a "rel=alternate" on every page.
This relationship is transitive — that is, if a document links to two other documents with the link type "alternate", then, in addition to implying that those documents are alternative representations of the first document, it is also implying that those two documents are alternative representations of each other.
Source: [w3.org...] http://www.w3.org/html/wg/drafts/html/master/links.html#rel-alternate (I 'broke the link' in this one to keep the anchor intact for a copy/paste.)
And here's where I start to feel like my username (lol).
The question you're asking really gets into the "micro handling" of documents Google (and others) have in place for different variations of markup combinations.
My gut tells me if they're all "alternates" and the use of rel=canonical is to identify "the best default choice" (preferred version), using rel=canonical on all 3 will likely cause it to be ignored in relation to the 3 versions you have, cause you're essentially saying each of 3 alternates (near duplicates) are the preferred version of the same page/content and that really doesn't make complete sense (especially from an algorithmic perspective in my opinion anyway), but it may not be ignored in a situation where someone else duplicates your content.
I really don't know the answer though, cause it really comes down to how they have decided to handle that type of situation but the above is my "best gut guess" on what they'll do with it algorithmically.
Another way of saying what I think will happen:
It will be ignored on your site since you're saying each of the 3 alternates (near duplicates) are the preferred version of the page. (Doesn't quite make sense, cause it doesn't seem like they really can all be the preferred version at the same time when they're alternates.)
It may be helpful if your pages are duplicated by someone else, cause then you're saying the preferred version of the exact duplicate of any of your original language variation pages is the original language variation page you created. (That makes way more sense to me, so I think it's more likely they will take the canonical into account in that situation.)