Will "Cortana" push Google to make Google Now better?
Not trying to be inflammatory here - just thinking aloud.
When I look at the demos of Cortana, it seems clear that Microsoft is playing catch-up with services like Google Now. (The same could also be said for other aspects of WP 8.1, such the notification tray.) However, the fact that Microsoft is the last of the three major mobile OSes to introduce their "assistant" feature means that Microsoft has an advantage of sorts: it means they've had more time to study how people use these sort of features, and figure out how the UI should work. And I think they have some good ideas.
In particular, they've directly addressed one of my main annoyances with Google Now, which is the fact that the service remains something of a black box. Yes, you can tweak certain settings by tapping the magic wand icon, but there are other aspects of Google Now that are very opaque. For example, you have very little control over the "research" and "website update" cards, which alternate between being freakishly perceptive and strangely terrible in terms of the content they select. (Ron Amadeo has complained about this too.)
I suspect that the "black box" nature of Google Now is a matter of deliberate design philosophy. My sense is that Google wants the service to have relatively few options because their whole concept for Google Now is that it should just do everything on its own. (If you allow Google to track your search history, obviously.) They want it to be a "magical" experience that "just works".
However, it seems like Cortana goes in a slightly different direction, allowing more granular user control over the type of information it displays. And it looks like it works pretty well. Honestly, I hope that Google learns something from the competition here - namely, the fact that it is possible to offer more granular control without creating excess complexity.
(On a similar note, I have a related complaint about a broader lack of options in stock Android, but I'll save that for another post.)