Legacy to service oriented architecture ( SOA ) migration

I would like to start a debate on the topic of migrating – Legacy – applications to SOA. Here are few thoughts to start with

Only minor changes in the code are required (I know it depends on what we mean by legacy code COBOL/4GL/Standard JAVA /C)?
What to look for in your legacy code to identify as a good candidate of being exposed as a web service (being loosely-coupled for example?)
The best way is to convert to one of platforms that support SOA such as .NET and J2EE, if that is feasible?

Any comments/thoughts are welcomed