I am trying to complete a seemingly simple task that has turned into a several hour adventure: Getting @@Identity from TableAdapter.Insert().
@@Identity
TableAdapter.Insert()
You'll need to setup the insert to return the identity as an output value and then grab it as a parameter in your adapter.
These two links should get you going:
http://www.akadia.com/services/dotnet_autoincrement.html
http://msdn.microsoft.com/en-us/library/ks9f57t0.aspx