With the news of PRS-700 shipping notifications I decided to check the Sony source code repository (http://www.sony.net/Products/Linux/) again and lo and behold: the PRS-700 sources are up! I did initial investigation and figured out some of the specifications of the new device.

CPU: Freescale i.MX31L, ARM1136JF-S core, 400-532MHz
EPD controller: Broadsheet (Epson S1D13521)
USB: MX31 USB OTG controller w/ High Speed Philips ISP1504 transceiver
Sound/Real-Time Clock/Battery/Power Management IC: Wolfson WM8350
Flash cards: MX31 SDHC controller, MX31 Memory Stick controller
RAM: 128MB
Flash: 512MB NAND
Linux kernel: 2.6.23 (compiled with gcc 4.2)

For comparison, here's details for PRS-505:

CPU: Freescale i.MXL, ARM920T core, 150-200 MHz
EPD controller: Metronome (E-Ink 8T125100A)
USB: Epson S1R72V17 USB OTG High Speed Controller
Sound: Asahi Kasei AK4356 DAC
Flash card interface: Ricoh R5C807 SDHC/MemoryStick controller
RAM: 64MB
Flash: 256M NAND + 2MB NOR
Linux kernel: 2.4.17 (compiled with gcc 2.95.3)

The CPU and RAM doubling are good news. Maybe the 700 will actually be able to handle more complex documents.

Wrote a few more comments (http://igorsk.blogspot.com/2008/12/prs-700-internals-and-disassembly.html) on my blog after having a look inside.