Feldon 
The database migrations continue, this time with Antonia Bayle and Everfrost. From the EQ2 Forums:
The Antonia Bayle and Everfrost servers will be brought offline on Thursday, April 2, 2015 at 2:00AM Pacific* for server migration and maintenance. These servers are estimated to be unavailable for at least 12 hours.
Keep an eye on the EverQuest II forums and social media for status updates and for news if additional downtime is needed.
So, anyone from migrated servers noticed any benefit (faster zoning, less lag or whatever)?
To be honest I really can not tell any difference. I had an odd thing happen in broken skull bay last night where the sound spazzed out like it had lagged. But the spell lag is still the same. Nothing really looks faster. However I not raided in 9 months and that is where most of the lag is. Possibly maybe ask a raider if they raid zones are better as far as lag/
EnterpriseDB has an Oracle compatibility mode.
http://www.enterprisedb.com/solutions/oracle-compatibility-technology
That will allow them to run the database practically as is without having to modify the data types or change much of any stored procedure code.
So unless the PostgreSQL engine is that much more efficient than Oracle or they did some data structure optimizations, this was most likely just a cost savings effort. (EnterpriseDB licensing is cheaper than Oracle licensing.)