The architecture of Power Center 8 has changed a lot:
1. PC8 is service-oriented for modularity, scalability and flexibility.
2. The Repository Service and Integration Service (as replacement for Rep Server and Informatica Server) can be run on different computers in a network (so called nodes), even redundantly.
3. Management is centralized, that means services can be started and stopped on nodes via a central web interface.
4. Client Tools access the repository via that centralized machine, resources are distributed dynamically.
5. Running all services on one machine is still possible, of course.
6. It has a support for unstructured data which includes spreadsheets, email, Microsoft Word files, presentations and .PDF documents. It provides high availability, seamless fail over, eliminating single points of failure.
7. It has added performance improvements (To bump up systems performance, Informatica has added "push down optimization" which moves data transformation processing to the native relational database I/O engine whenever it is most appropriate.)
8. Informatica has now added more tightly integrated data profiling, cleansing, and matching capabilities.
9. Informatica has added a new web based administrative console.
10. Ability to write a Custom Transformation in C++ or Java.
11. Midstream SQL transformation has been added in 8.1.1, not in 8.1.
12. Dynamic configuration of caches and partitioning
13. Java transformation is introduced.
14. User defined functions
15. PowerCenter 8 release has "Append to Target file" feature.