We have had a number of requests for a DNN integration, but we have too much on our plate to do it ourselves.
SplendidCRM is probably well suited for integration as all of its core logic is already inside a user control. This design has allowed us to quickly transition to .NET 2.0 MasterPages.
One issue is that the installation of the combined products would have to use the SplendidCRM installation system to ensure that the SQL source code remains encrypted.