it wont help you - but i'm expericiencing a similar problem i think - see
a couple of messages above this - however i started by gettin the RHDS beta with the mebedded 42.1. server - and when i create a seam project it - the project is auomatically in error saying the server doesnt support ear v5 facet.
I've not tried yet pulling in jboss tools into a europa eclipse 3.3 build and seeing if that has the same problem - however it sounds as you are experiencing a couple of issues doing it the latter way.
I cant find a jboss v5 beta2 server adapter for europa that will launch the as without error in eclipse - so i havnt figured out how to try deploying to a jboss AS v5 vs a AS 4.2.1 config.
any one who could help on that topic - i'be bet interested to here where to and install a working v5 adapter for eclipse