The XScale CPU seems to become the successor of the StrongARM CPU. For technical information see the resources by Intel(http://www.intel.com/cd/ids/developer/asmo-na/eng/strategy/phone/index.htm) .
The successor to the Zaurus SL-5500(pda_linux_sharp_sl5000.html) has been introduced, but only in Japan, and the bad news is that Sharp(http://www.sharp.co.jp/) representatives say there are no plans to bring it to the United States. "The Zaurus SL-A300 measures 0.5 inches by 2.7 inches by 4.4 inches and weighs 4.2 ounces. It uses Intel's 200MHz XScale PXA210 processor, 64MB of memory and a 3.5-inch active matrix display with a resolution of 320 pixels by 240 pixels. It also has a Secure Digital slot for expansion." Product information(http://www.sharp.co.jp/products/sla300/index.html) (in Japanese).
The X-Scale uses the arm5 instruction set which is a superset of the arm4 (SA11xx) instruction set. GCC 3.1 has a compile option for the X-Scale CPU.
In the Memory Technology Device (MTD) device section of the Linux kernel you may find a switch to enable the "access routines for the flash chips on the Intel XScale IQ80310 evaluation board. Anyway there is much more to do to get the bootloader and the peripheral devices to work with Linux.
Jelie(http://lapwww.epfl.ch/dev/arm/jelie/) is a JTAG port driving software for the Intel XScale CPU family. With only a JTAG connection, Jelie is able to upload a debug handler, initialize the memory, upload and debug programs. Jelie can reach the JTAG port of the target processor trough a parallel port and a OCDemon McGraigor Wiggler adapter. A USB connection using Anchor's EzUSB is also possible. Jelie understands GDB's serial protocol on a TCP/IP port.
Other PDAs with X-Scale CPU, wich will be delivered with Microsoft PocketPC 2002.