If you just want to talk to a remoting destination in BlazeDS this is not too difficult. Here is a blog posting that Mete (one of the developers on the LCDS/BlazeDS team) wrote that describes how to do this using the NetConnection API.
If you wanted to do pub/sub messaging that would probably require back porting quite a lot of the BlazeDS messaging code to AS2 which I imagine would be quite difficult.
Hope that helps.
Just wanted to thank you for your post... Exactly what I needed.