Unfortunately yes. The two do not "speak" a compatible language. However if you make diligent notes of fonts, colors, images, general layout you should be able (if you are using a three column theme-old editor does not natively support two column layouts.) to come pretty close to replicating it. The content will transfer but you may have to work on the formatting. All in all a decision not to be made lightly....
Robert, first HEY! :)
Did you go with the New Design Editor and have issues w/S4N Magic Text Boxes?? That's my big issue, I do not want to lose them.