Virtera has released version 1.0.0 of its Zaurus emulation software. You can get the demo version from http://www.virtera.com for free! The software is called VirtualMHz for ARM and the Zaurus emulation is only one part of it. In general, it's a general-purpose simulator of the ARM architecture and implements the SA-1100 as its first micro-processor and Zaurus SL-5500 as its first platform. It uses dynamic instruction translation so performance is pretty good - on a fast enough PC, you can emulate an SL-5500 in real-time!
Previous versions were available as beta tests for 30 days. The demo version is now time unlimited and fully featured. In fact the demo version only lacks some of the debug and developer mechanisms of the full product (which has not been released yet), but everything else is included. This is a proprietary product and not based on open source. The software only runs on Linux on a PC. Sorry, no Windows version yet.
If you're interested, check it out at:
Follow the link for Software Download. You need to fill in the download form to access the software. There are also various documents and the whitepaper available for download, plus a FAQ and bulletin board.