So here's my cockeyed theory about the calendar release (or lack thereof):
They did intentionally leave off the add/remove features to try to make the iPod less iPhone-ish. People got mad, and they want these features. So Apple will update...but not quite yet.
Why not yet? Think about the iTunes music store for the iPhone. Good ol' version 1.1.1 brought the iTunes store to your iPhone, and it's such a nifty feature that people wanted to update badly, so they did. And hacked iPhones got bricked.
I think that they're waiting until the iPod Touch has been hacked to release this "can't live without" feature, and in the process they'll break your hacks and fortify the OS against similar hacks. I don't think they'll brick the Touch, since it doesn't really affect them one way or another what you do with it (there is a risk if people are able to hack the wifi iTunes store, but that activity would probably be tied to your account anyway). Also, they're catching a lot of heat about the iPhone bricks.
Anyway, that's my $.02. Nothing like a good cockeyed theory every now and then.