We have just released the Biztalk adaptor for MS CRM 4.

It can do pretty much the same as the adaptor for CRM 3 but this one support 64 bits natively

You can download it free of charge from this URL:

http://www.microsoft.com/downloads/details.aspx?FamilyId=ABD3BB9E-A59A-4EB6-8DE8-FB25B77926D7&displaylang=en

Now go and upgrade that Biztalk server :)

Over and out.