I'm sure that Team Marketo is working on some subscription method like this, but I didn't notice a community idea for it already existing.
I'd like to be able to subscribe to an internet calendar definition of the Marketing Calendar via Exchange, Office365, Gmail, etc., much like I can for projects within Basecamp. Being able to see it within the Marketo platform is great, but I'd like to have events in the Marketing calendar syndicated with my other calendar(s) as well.