*Warning - this post is heavy on the images, but it's to make things easier for all of you following the tutorial.
Convert a Silhouette file to Adobe Illustrator
1. Open the Silhouette file you want to bring in to Adobe Illustrator.
2. Ungroup the image, fill the shapes in with black and change the line color to none.
3. Make sure no shapes are overlapping unless you want them to become one shape in Illustrator.
4. If there is negative to a shape that it is white NOT black.
5. Open the Print Dialog in Silhouette and choose "Adobe PDF". Then click on Preferences. Select the Paper/Quality Tab, set the color to Black & White and then select Advanced. Change the Paper size to "Postscript Custom Page Size" and then set it to 12x12". Press OK, OK, Then Apply and Print. Choose the name and location for your PDF file and save it.
6. Open Adobe Illustrator and Open your new PDF file in Illustrator. If you select them image you will see that your image is broken into a bunch of squares. That's not exactly what we want, so there's just a little more work to do.
7. Go to Object->Rasterize to flatten the image completely. Choose Grayscale and Transparent Background. Don't freak out as you see the edges get a little messy on the shapes. That will get better in the next step.
8. Click on arrow beside Live Trace and go to Tracing Options. Check the box beside "Ignore White" (this step will save you work later). Click on Trace. See how the edges cleaned up? It's still one complete square though.
9. Click on Expand. Now you have all of the objects as shapes in Illustrator! Of course, they are currently all grouped together so to work with them individually you may want to ungroup them.
Best of luck as you try this out! Let me know if you have success!
For those of you wondering why there's a need to bring a shape over to Illustrator when it's already in Silhouette Studio - there are a lot of fun tools in Illustrator (patterns, fill options, shape editing) that are not available in Silhouette Studio. That combined with the ability to cut directly to the Silhouette from Illustrator have a lot of designers sticking with Illustrator!