I was recently visiting a customer in Latin America discussing what a target architecture would look like given that some of the code would migrate over 'as-is' in Cobol, and some new work would be done in Java, while at the same time, the 'new' system would need to integrate with existing mainframe technologies.
This is a combination of both WebLogic (for Java) and Tuxedo (for the rehosted Cobol) as well as our SOA Stack for integration and new Business Processes. Below is an excellent slide that Mark Rakhmilevich recently provided on what this target stack looks like.
You can see in this picture, we have the various layers all built on 11g Grid Technology.
The Oracle technology stack starts with the database grid, which is the cornerstone for data management. The next layer up is Application Infrastructure comprised of Oracle Tuxedo and WebLogic, which are two application platforms in OFM that host business logic – Tuxedo hosts re-hosted COBOL and C/C++ and WebLogic hosts Java for extended services, new components, etc. Both provide high degree of SOA capabilities and integrate with the Oracle SOA Suite technologies shown in the Services Infrastructure layer, and standards-based service networks. These technologies together enable re-host, expose, re-architect, extend, and re-use approach that we've gone over in this blog.

If you need to explore more on Oracle Modernization, you can search this blog or take a look at www.oracle.com/goto/modernization