Yeah, I updated my original post shortly after reading more about the game:
"Maybe you weren't being sarcastic! I'm not familiar with Cave Story. What's it all about? How does it play? You've gotten me interested now."
I also posted a follow-up:
"Thanks for the link. Cave Story looks better in motion. The screenshot I saw doesn't do the game justice."
I'll give it a shot when it comes out.
By the way, there are already several great titles that justify WiiWare. See my list:
http://www.digitpress.com/forum/showthread.php?t=109135