http://www.ids-scheer.com/us/en/News/IDS_Scheer_Previews_Integration_of_ARIS_Platform_and_Microsoft_BizTalk_Server/86824.html?referer=32430
Available sometime in 2008.
Future releases of BizTalk will use the .Net WF engine - just imagine the possibilities. A free workflow engine that integrates with ARIS and can run on the desktop, app server, web server, SharePoint, MS Office & integration tier. Not to mention the army of .Net developers in the market gaining experience on .Net WF development and the wave of blogs, code, wiki's and training available.