Yep, it's the original. I don't remember how often it's supposed to be changed... but the guy before me did his own service, Ski Masters didn't mention it when they winterized/dewinterized last year. I dunno...??
Festivus, I'm a mechanical idiot too, by the way. I had to get a local Toyota mechanic to remove the hoses for me (mine were fused on because of the factory paint). Once I got the hoses free, this is about an hour-long deal. I was blown away at how easy this is. It looks scary... but it's a piece of cake.
One thing to add to Pete's instructions -- i had to also remove the three screws from the base of the master power switch (on the passenger side of the engine in my X22). I'm guessing Pete's might have been in a different location than mine. Pete, thanks for the instructions, they rocked.

Oh, got my impeller at Go2Marine.com. The factory original is a Johnson 812. But the one that I ordered is a Jabsco 13554-0001. I know that when you search their site for a Johnson 812 it shows up.
When I get a few minutes, I'm going to update all the part numbers that have changed, and where I got them from, so that it will be in one list, rather than a bit of searching to figure out part numbers, etc.