V3 TP2 does not support ear or ejbjar modules, so there is no NetBeans tooling support enabled for those projects at this time.
You can however, create a webapp that contains session beans (ala Ejb 3.1, under development). You'll have to use the V3 TP2 update center to download the ejb container into TP2 (right click your TP2 instance node in the IDE to get started) if you haven't aready.
There is no tooling support in NetBeans (yet) for Ejb's within a web app but you can create java classes and add the annotations manually.
See also
http://blogs.sun.com/MaheshKannan/entry/ejb_3_1_in_glassfish
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