I passed (the beta) without any studying. It is a different exam to SCJP, testing different things, it is not enough to be able to pass SCJP, you have to know things that are not covered (a load of mobile java for example).
Depends what you know already? I found SCJA quite easy, but you do need to know a little about a lot of technologies. If you have worked on J2EE, then this exam should not be too difficult.