A question for you guys who already jumped the train: when you install Mountain Lion on fusion drive, does it create small recovery partition? Or you end up with a single volume in boot options?
You know, you could always clone your boot volume to another volume using Super Duper or Carbon Copy Cloner, boot from that, create the fusion drive out of your old boot disk + the second disk (or partition or whatever), clone the backup back to the fusion drive, and reboot. Easier than reinstalling.
Yeah, I just have my installer on a Flash drive.