Sun Application Server 9.1 / GlassFish V2 are being released. (FCS)
By User12608895-Oracle on Sep 17, 2007
Java EE 5 SDK Update 3 now is released which have included Sun Java System Application Server 9.1 (FCS - final release). And this is based on GlassFish V2 which have clustering support.
If you are interested download from this URL and it is FREE.
(Free! for Development and Production)