#6 In-memory is now table stakes
One of my (rejected) themes was in-memory enablement. Microsoft and Oracle followed SAP into mainstream in-memory database support in 2014. Oracle had TimesTen previously, but that's a niche product used for industry apps in telco. The 12c In-Memory Option is for any app -- the biggest performance gain is for analytic apps (claimed to be 10x to 100x) while transactional gains are more modest ("at least 2X," according to Oracle). Microsoft's SQL Server In-Memory OLTP option is, as the name suggests, all about transactional app performance improvement.
If you have apps the require the crunching of lots of data (dunning, production planning, forecasting, etc.), these in-memory opitions let you store specific tables in memory for much faster performance. SAP Hana is all-in-memory, but it has interestingly introduced an option to put selected information that is NOT important or hot on disk for lower cost. Bottom line is enterprise apps are no longer constrained by data and I/O bottlenecks.