This is such great news, it deserves a post of its own. The Sextante Blog
has released a video
showing Sextante integration with ArcGIS. While I haven't seen the full list of tools, I've every reason to think it will include all the Sextante tools, which would for many people obviate the need for an
ArcGIS for Desktop Advanced license, as well as Spatial Analyst, Geostatistical Analyst, and maybe others...
Tremendous news, indeed.