After we linked to instructions for how to burn a Lion boot disc earlier this week, Nature's Eye Studios contacted MacStories to let them know they figured out how to get the new OS to boot off a SD card. After downloading Lion from the developer site, the video maker proceeds to wipe a SD card and use the repair option with the Lion disk image as the source to create the boot. Once you've created the backup, you can use the SD card as a Lion installer if needed, then pull a backup from Time Capsule.
Keep in mind that the final release of Lion