Updated 2: SmallNetBuilder has learned of a new dual-core five-bay SMB-focused NAS from Synology.
The DS1010+ and companion DX510 expansion chassis appear to be updated versions of Synology's DS509+ and DX5 expansion chassis.
Synology specs the five-bay 3.5" SATA NAS at "116+ MB/sec reading speed under RAID 5 configuration in a Windows environment, and 103+ MB/sec writing" according to a product page posted on its Chinese-language website and a downloadable data sheet.
The excerpt from the data sheet below shows a 1.67 GHz dual-core CPU, 1 GB of DDR800 RAM, dual Gigabit Ethernet LAN ports, four USB 2.0, one eSATA and a
serial console VGA port.
Although Synology doesn't identify the CPU, the specs point to an Intel Atom D510. This would give Synology a five-bay competitor positioned between QNAP's recently introduced TS-459 Pro and TS-639 Pro D510-based NASes.
1/15/2010 Update: Synology confirmed the D510 as the CPU.
It looks like announcement is imminent, since Amazon's product page for the DS1010+ is showing a January 21 release date.