Well ... must probably wait until PDC to be able to discover the positioning between both technologies, but some comments and guidance are posted at:
https://blogs.msdn.com/darrenj/archive/2008/10/01/dublin.aspx
http://geekswithblogs.net/MainaD/archive/2008/10/06/125675.aspx
http://www.microsoft.com/biztalk/en/us/roadmap.aspx
http://www.microsoft.com/net/Dublin.aspx
PingBack from http://www.easycoded.com/dublin-and-biztalk/