Import and Export Wizard with Identity Column
Solution 1:
You'll need to Enable identity insert. There's a check box when you click the Edit Mappings.
Solution 2:
Byte56's answer is correct - check "Enable identity insert" from the Edit Mappings screen. I just wanted to point out that the "Select Source Tables and Views" list supports multi-select, so you can hold down Shift or Ctrl to select multiple tables in the list.