New Galaxy server--the X4600--coming soon?

I've just been perusing Sun's documentation site, looking for X4200 documentation. At the page that lists the servers, I noticed an entry for the Sun Fire X4600.

Given that the X2100 is two core 1U, the X4100 is four core 1U and the X4200 is four core 2U, I reckon the X4600 is a four core 6U machine. What that extra 4U buys is anyone's guess, but I suspect that more SAS drive bays would be top of the list, and perhaps a memory expansion card. A CPU/memory card also fill some of the space, but that would go against the naming convention (assuming I parsed it correctly, of course!). Time will tell...