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 ArcInfo ArcGIS for Desktop Advanced license, as well as Spatial Analyst, Geostatistical Analyst, and maybe others...

Tremendous news, indeed.