As I understand it, SP 2013 will run on .NET Framework 4.5. Claims-based authentication runs on WIF. In .NET Framework 4.5, WIF (2.0) has been substantially updated (changes).
How will this update affect the current SP 2010 Web applications using Claims-based authentication (which was based on WIF 1.0)? Has anyone performed such an upgrade? Is the upgrade process trivial?
Upgrading a Windows claims web app from 2010 to 2013 is the best authentication scenario I could picture. I expect Microsoft has done the most testing on this route and will have a lot of support for it at release. The only outlier I've noticed in the TechNet docs so far is the FBA claims from 2010 to 2013 called out as a special case.
Upgrading SharePoint 2010 to SharePoint 2013 in general, is somewhat manual unless scripted. It's a database upgrade approach, which requires creating new web applications, installing and configuring service applications and applying customizations before copying the databases over to the new server and adding them to the new farm.
I havent done it myself but will have to soon :( when upgrading the system from 2007 to 2013! but I do know its not as much work if your 2010 is already running on claims-based authentication rather than classic-mode web applications as classic-mode web applications is no more in 2013. From what I can see it will be some work to migrate from the two. For one its now intergrated into the .net framework. Some parts have been changed vastly even redone completely.
As 2013 is new there really is not much documentation untill the full release.
Check this link out as it shows the upgrading from 2010 to 2013: http://technet.microsoft.com/en-us/library/gg251985(v=office.15).aspx
I hope this answers your question :)
