Doing that well is difficult, and (worse still) when it breaks down, it's typically very irritating. There is a sort of uncanny valley of automated helpfulness, where sincere attempts to assist common interactions just end up feeling like Clippy to end users.
Exactly, I thought that was the point of the article. We need "indexing by meaning" - for unix utilities, for iPhone apps, for words.
For instance, I'm looking for an iPhone app that let's you take pictures of people, add names and details, and let's you browse them by picture. I bet something like it exists, but I can't find it.
Well, one could catalog a whole bunch of such situations in Terminal.app on OS X, just for example. Create a catalog of situations as described in the article, so that those entry patterns can be detected. A "suggestion" or "coach" app could then start bouncing in the Dock, letting you know that you can click on it and get a list of selections. (Or, you could just blow it off.)
Being watched feels kinda creepy. But being able to find the stuff you want is fun.
To a certain extent, this is somewhere where GUIs out-perform command lines - the hierarchical menu system that shows you the functionality available in a way that's fairly easily searchable. Maybe you could implement some sort of tree-structured help on the CLI?
Maybe we could figure out a thingy that watches what you're doing and finds ways to do it better.