The first post-R3 cumulative update, Cumulative Update 8, is now available for Microsoft Dynamics AX 2012 R3. This release contains all of the fixes from AX 2012 R2 plus new fixes introduced on top of the R3 platform. The build for this release is 6.3.1000.309.
I encourage you to check out the TechNet page that articulates the new features released inside CU8: http://technet.microsoft.com/EN-US/library/dn762135.aspx. There’s a more detailed review of the warehouse and transportation features on the Supply Chain Management blog here: http://blogs.msdn.com/b/dynamicsaxscm/archive/2014/11/19/what-s-new-in-cu8-for-wms-and-tms.aspx.
Before installing it, you should review the Install Guide available on Microsoft’s download site here: http://www.microsoft.com/en-us/download/details.aspx?id=44953.
With the new “Updates” feature inside Lifecycle Services (read more about Lifecycle Services on our blog at /lcs), you can actually Slipstream CU8. You can also download the install package directly from Lifecycle Services: https://update.lcs.dynamics.com/Download/Index/834550. My recommendation is to use the “Upgrade Analysis” feature lower on that page to understand the impact of the upgrade on your customized code. You can then put together your project plan around the upgrade after understanding how much customization would need to be done.
Good luck with your upgrade and let us know if we can help.