We've added a new small widget called Oder Summary which can be added on a page or popup after a checkout to show a summary of the order made. It will automatically be added to all system 'order complete' pages ONLY IF they haven't been modified in the past. It also works with funnels and upsells/downsells as steps.
Next time your editing a thankyou page, look for the new "Order Summary" widget which will dynamically show all contents of the order (bumps/upsells/downsells) included.