I don't know how closely they're going to mirror the Guild Wars 1 alpha/beta test, but if they end up doing it the same way, the Beta Weekends are going to be "closed" (but really open to most anyone who wants in) with no NDA (but only a small, fairly polished slice of the actual game available for play), but the actual, full-game, full-time test is going to (continue to) operate under a rather strict NDA (I had to send in a physical, non-facsimile, pen-signed copy of the NDA agreement, along with a photocopy of my birth certificate/driver's license, when I got in, and the closed-test version of the client had a faint watermark of my e-mail address across the whole screen).