With all the upcoming blogs about NAV2013R2, ik makes sense to start with where you can start: what did Microsoft already foresee to get you ready for NAV 2013 R2? Well: there is a readyness page, like ther was for NAV2013. And you can find it here: https://mbs.microsoft.com/partnersource/training/news/MSDNAV7GettingReady.htm
And you’ll see – it’s the same page as the NAV2013 readiness page, extended with some links to readiness library for NAV2013R2 on multiple domains:
And you’ll find all kinds of things: Powerpoints, “How Do I”-video’s (which will be published on youtube when the product is released), factsheets, blogs, … . All you need to get ready. Personally, I like the video’s .. because they are really to-the-point! A lot of effort has been put into it (believe me .. I know …).
I contributed as well 
As I stated in an earlier post .. I’m proud to say that I have been working on some of the “How Do I”-video’s in collaboration with Plataan . And I hope you like them:
- How Do I: Manage Companies in Microsoft Dynamics NAV 2013 R2
- How Do I: Migrate from Multiple Companies to a Multi-tenant Architecture in Microsoft Dynamics NAV 2013 R2
- How Do I: Align Controls in a Report in Microsoft Dynamics NAV 2013 R2
I also created a video about backup/restore in a multitenant environment, but I didn’t find that on the Readiness page (yet?). I promise you that it will get online at some point – or I’ll do a blogpost about it. I’ve put too much research into it to not publish it 
.
Conclusion
So, bottom line: You might not have the database (which I have been told that will come quite soon), but there is already tons of materials to get yourself ready for the next release!
Enjoy!