Great post and probably my favourite round up type post I have read. I think you have nailed everything and also cited a lot of great resources for people to refer back to. I completely agree on Schema and Authorship being big plays for 2013. I am also really interested to see how the Disavow saga plays out next year. I think Google has created issues with the penguin update that is still going to be a problem for some sites next year (in terms of getting blasted with bad links). It may only be a few cases. But after watching Matt Cutts video on this (negative SEO). I am pretty sure, if done properly, you can tank a site.
Great stuff, Gianluca! Especially the bit about mobile - it's definitely time to pay attention to it.
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