This question was asked in a comment on WAS 6.1 Now Available. The WebSphere Adapters are part of the WebSphere Business Process Management suite of products. Specifically, they're the newer WBI Adapters that are reimplemented to be J2EE Connector Architecture (aka J2C) compliant. So, WAS is J2C compliant, the Adapters are J2EE compliant, so do the Adapters work in WAS 6.1?
In a word: No. The Adapters are J2C compliant, but they also require some extra stuff, like the business objects (InfoCenter) framework in WebSphere Process Server and WebSphere Enterprise Service Bus.
WAS 6.1 doesn't contain the business object component (nor some other code that the Adapters require); the SCA, business objects, and CEI components are built on top of WAS ND, not within it. So the Adapters cannot run in WAS 6.1.