Yesterday Oracle released SOA Suite 10.1.3.5.1, the version which you can install on Weblogic 10.3.1 (the FMW11g version). This version can be a between step before you go upgrade to the FMW 11g version. Now you don’t have to change you BPEL and ESB processes (don’t need to think about SCA) and just deploy this on the new WLS SOA Suite server. Off course you need to have Weblogic knowledge and configure the resource adapter, datasources, JMS and the foreign servers. But you get as benefit a reliable, scalable application server and your organisation get some experience with Weblogic before going to FMW 11g.