Okay, here's weird.
You can move the original Wii Speak channel to the SD Card - but you can't move it back, the system tells you to download the new version. You can run the old version from the SD card. You can download the new version and keep it on the system and run it.
Now, if you have 1.0 Photo Channel and downloaded the 1.1 update, you can move the update to the SD card and 1.0 will reappear on your Wii Menu. However, there is no option to run 1.1 from the SD Card.