A very quick, down and dirty, trick might be to save the 2D information as an image and simply insert it into the SW drawing.
But, you should be able to manipulate the SW BOM to show the same data as the 2D version.
A longer term alternative is to create a set of dummy (empty) components in a SW assy, and arrange them to suit the 2D BOM.
SW Labs has a product called Treehouse which would be perfect for this. http://labs.solidworks.com/Products/Product.aspx?name=treehouse
When time comes to create the 3D parts, the geometry can be created in the dummy parts.
This looks very interesting. For future 2D to 3D applications with only partial conversion this seems like a good idea. I just downloaded it and hope to find time to try it out. Many of the reviews referring to lack of functionality appear to be attempting to use this tool for more than what I'd need. Thanks for the tip.