Details and Conditions
From Mojang's Commercial usage guidelines:
"If you comply with and follow the Essential Requirements (in the Brand and Asset Usage Guidelines) and Naming Guidelines, YOU MAY create, use, and distribute videos and streams of you playing or using Minecraft for any lawful reason, and YOU MAY make money from them by adding or permitting advertising in them, so long as:
all video downloads are free to view (i.e. there is no pay wall or other charge to view the videos);
all streams are made free to view within 24 hours;
you add your own unique content to the video or stream, such as audio commentary or footage of you making cool stuff;
you don’t create and use videos or streams whose purpose is to advertise or promote other products or services;"
To see more details and rules, including a naming guideline for titles, click the "source" link below.
What it Means
Videos and streams ARE allowed
You CAN monetize on YouTube and Twitch with ads and subscriptions
You CANNOT sell or charge for access to your content unless you make that content available for free for everyone within 24 hours (this would include Twitch "subscriber only" streams)
Any licensed IP or music not owned by the publisher are not covered by this policy
You MUST add additional commentary or unique content
You CANNOT promote or advertise any products or services