I just came across the following update on BizTalk service labs web site

I will try to include a sneak peak on BizTalk services in my “Composite Architecture” & “WCF Services” presentation at Pakistan Developer Conference.

June 8th, 2007: BizTalk Connectivity Services and SDK Update

BizTalk Connectivity Services now supports:
UserName/Password based authentication
Access to application services through any web browser

The SDK has also been updated with:
Samples showing how to use username/password authentication
Samples showing how to expose a service so it can be accessed through a web browser
Compatibility with .NET Framework 3.5 Code Name “Orcas”