This dropped into my inbox the other day, built on the same Infrant and SuperMicro platform that ReadyNAS pro currently are, this seems to be an attempt to raise the bar a bit for Netgear.
It looks like this will be made available in a diskless form supporting the SSD/SAS/SATA of your choosing. (Although it says they have to be Netgear Shipped).
RD5200

But at $10-15k (I expect thats without disks) it will be interesting to see where it slots in with the likes of Sun, QNAP, EMC and the lower end HP SAN kit but at least it looks like all of the toys such as dedupe and block level replication are included in the price.

ReadyDATA 5200 FAQ

Released to the UK channel tomorrow, keep an eye on the tech press for more details.
Yet another cat gets let loose amongst the already struggling pigeons...