Available via Books Online are the list of features supported by the different editions of SQL Server 2014. Some of the highlights (or low-lights depending on your opinion) are that SQL 2014 Standard Edition is still set to 64GB limit of RAM per instance, the same since 2008 R2. Data storage is also at 524PB, which is a frankly huge amount. Important to note that in a virtual environment the maximum size a .vhdx disk can be is 64TB.
w/r/t to Enterprise, SQL Server virtual machine is still pegged at 64 virtual processors and 1 terabyte of memory. This is the maximum supported by Hyper-V 3. Physically, the limits are at 640 logical processors memory is set at 4TB respectively. These constraints are the limits of the Windows Server 2012 OS.
Partitioning, compression and Resource Governor are still exclusively available through Enterprise licence only.
Both Enterprise and Business Intelligence are the versions to go for if you are planning on building Data Warehouses/ Analysis Services with Standard still with the same features from SQL Server 2012. In fact, if you’re upgrading from SQL Server 2012 to SQL Server 2014, all of what I have listed is the same for Standard in both versions. Something like doubling the memory limit would’ve been an incentive for some people… maybe? Frankly I bet most people upgrade to Enterprise for features like partitioning and compression, not unlimited memory. I appreciate that at $7 per core there has to be real incentive to upgrade form Standard to Enterprise , but if memory is your sole bottleneck you’d probably look at other alternatives first.
No info on what version we should expect to see In Memory OLTP . It is noted also that this list is subject to change between now and release. SQL Server 2014 is available for 180 day trial via Microsoft’s download site.