Microsoft’s Cortana is certainly a work in progress, even here in the US where it’s officially available. China and the UK are on the immediate horizon for rollouts, with other regions to follow soon. With all of that work ahead, it makes sense that the Cortana team will want to have a regular update schedule, and much like the Xbox Music app, it looks to be bi-monthly.
In an interview over at Engadget with the Cortana team, updates to the Cortana system will evidently happen twice a month with the possibility for off-cycle updates “for things that are timely, urgent or especially badass." The ability to update Cortana dynamically will ensure that her chitchat (small conversations pieces, voiced by Jen Taylor), will be current and relevant, reflecting any significant cultural happenings.