HT have the readynas NV+ version 2 for an insane price of $248 + shipping. This is a fantastic unit and has the robustness of the readynas product range.
The Marvell ARM cpu is still in it's "infancy" stage so there aren't as many addons as X86 or SPARC versions but it's very fast in comparison to the old SPARC NV+ I have.
HT has them in stock (in the warehouse) but available at the old price ($498), grrr. I received their email advertising this at 3am. Seems you need to get up at 6am and order online overnight, or just get angry. More like a 4 hour sale than a 48 hour sale.