Live from SharePoint Conference 2012.
SkyDrive Pro + Social features are the new SharePoint 2013 Personal Site.
Hosting MySite on SharePoint 2013 has not changed, meaning still need a web application with content database(s) which host the root site collection ‘My Site Host’.
Default quota for MySite on Office 365 is 7 Gb while OnPremises it’s 100 Mb.
Social
All Social data have been moved to the MySite Content database to allow better scale up; with SharePoint 2010 there was only one Social database while there may be more MySite content databases.
Discovery
SharePoint 2013 introduces a My Site discover process, allowing simpler personal storage provisioning, Office hub configuration on Windows Phone or Office client configuration… in some way this is identical to the Exchange Autodiscover feature to auto configure Outlook client to connect to your mailbox.
Provisioning
Personal site provisioning on SharePoint is now an asynchronous process. because of the many entry points which may triggered Personal Site creation in addition of the increase use due to Social features and SkyDrive Pro. This allow a better performance and higher number of provisioning requests.
Personal site is now mandatory for social.