See www.debwrt.net/downloads/testing/pre-2.0 for README and downloads. Unfortunately I still experience problems with b43 stability.
The b43 is now supposed to be stable for kernel 2.6, so no reason anymore to hold back DebWrt releases. This week a testing version will appear in the testing section of this site. A new release will be created after sufficient testing. Note: no 2.4 kernel based release anymore!!!
On June - 22 - 2010 News