APS 188.8.131.52 appears to have a significant new feature, Essbase Web Services. Here is an excerpt from the readme file posted on the Oracle website:
Essbase Web Services
Web services are self-contained, modular applications that one can describe, publish, locate, and invoke over a network. Web services allow access to regular applications using a Web browser. Web services use XML to code and decode data, and SOAP (Simple Object Access Protocol) to transport it.
Essbase Web Services will expose Essbase user and administrative functionality in a services-oriented (SOA) environment via Provider Services, and allow Essbase to be easily integrated with both Oracle and third-party applications.
The APS Admin Guide also posted at the Oracle site has information on the Essbase Web Services and what you can do with them. It appears you can query data and metadata along with performing some admin tasks. One thing that looks useful immediately is the ability to execute a Maxl statement via a web service. This would eliminate the need to install the Essbase client just to run Maxl statements; I have one customer who could benefit greatly from this functionality today.
Hopefully I will get a chance to play with these soon and post some sample code. On the other hand, ten years ago I wrote web services to retrieve Essbase grid data into Dodeca and they are *very* fast, so I don't see myself working very hard on those particular APIs.