Part of the upgrade and migration process is keeping your existing SQL Server instances properly patched. Being on a minimum Service Pack level is often required in order for some types of upgrade and migration operations. It is also required to be in a fully supported state from Microsoft. It is also just a good idea!
On August 8, 2017, Microsoft had a multitude of updates and new releases that are relevant for Windows and SQL Server. First, it was “Patch Tuesday” for August 2017, so there were a number operating system updates, Internet Explorer updates, Edge updates, etc. Then, if you have Microsoft Update installed (which is a superset of Windows Update), you would also be offered security updates to SQL Server 2012, SQL Server 2014, and SQL Server 2016 (for currently supported Service Pack levels).
Microsoft also released Cumulative Updates (CU) for SQL Server 2012, SQL Server 2014, and SQL Server 2016 (for currently supported Service Pack levels). The CUs also include the security hotfix offered by Microsoft Update (which also included the complete CU). So one way or another, if you took either update method, you should be fully up to date, whether you like it or not.
Actually, I think this is a good thing. Microsoft has been recommending proactive installation of CUs since March 24, 2016, as detailed in their Announcing updates to the SQL Server Incremental Servicing Model (ISM) post. As a consultant, I always advise people to regularly, explicitly install CUs on their own schedule, after they have done their own testing.
The Microsoft SQL Server Release Services blog has posts listing all of these new CUs.
SQL Server 2012
SQL Server 2012 fell out of mainstream support on July 11, 2017. Despite this, Microsoft decided to release SQL Server 2012 SP3 CU10 (with only five public hotfixes) on August 8, 2017, probably because of the security hotfix. They are also due to release SQL Server 2012 SP4 in September, which will have a lot of manageability and performance improvements back-ported from SQL Server 2014 SP2.
SQL Server 2014
If you are running SQL Server 2014, you have hopefully moved to the SP2 branch by now, since it has a lot of manageability and performance improvements. It will also be a “supported Service Pack” for a longer period.
SQL Server 2016
If you are running SQL Server 2016, you have hopefully moved to the SP1 branch by now, since it has the new programmability features in Standard Edition, and many other manageability and performance improvements. It will also be a “supported Service Pack” for a longer period.
SQL Server Management Studio
Microsoft also released SSMS 17.2 on August 8, 2017. They recommend that you use this version of SSMS, even if you are running a down-level version of SQL Server. It is officially supported all the way back to SQL Server 2008, but it should actually work pretty well on SQL Server 2005 and even SQL Server 2000.
I have a new Pluralsight course, SQL Server: Upgrading and Migrating to SQL Server 2016 has just been published. This is my eleventh course for Pluralsight, but the complete list of my courses is here.
Building on this online course is a new three day class, IEUpgrade: Immersion Event on Upgrading SQL Server, taught by myself and Tim Radney. The first round of this course will be taught in Chicago from October 11-13, 2017.
Here is a link to the complete series about upgrading SQL Server.