I have been working on some very exciting assignments offlate and one of the key ones which would like to share is the Migration from SOA suite 10g to SOA suite 11g.
There are various options for this including using Jdeveloper and ant script.
I prefer using a mix of both.
I would be sharing a detailed step by step instructions at some point but for now I am sharing these very useful links which I suppose should solve most of your concerns.
Have a look at the Oracle documentation for the upgrade project:
Oracle Fusion Middleware Upgrade Planning Guide 11g Release 1 (11.1.1)
Oracle Fusion Middleware Upgrade Guide for Oracle SOA Suite, WebCenter, and ADF 11g Release 1 (11.1.1)
Oracle Fusion Middleware Developer’s Guide for Oracle SOA Suite 11g Release 1 (11.1.1)
In addition there is a very good white paper by Ahmed which provides useful information.
I am in the process of compiling my own experience and should soon upload it here.