I had to go check this out for myself. And I aggressively bolded/italicized/underlined the important parts of this snippet from the new policy:
Your Rights in Subscriber Content:
Subscribers retttuain ownership and/or other applicable rights in Subscriber Content, and Tumblr and/or third parties retain ownership and/or other applicable rights in all Content other than Subscriber Content.
Subscriber Content License to Tumblr:
+ When you provide Subscriber Content to Tumblr through the Services, you grant Tumblr a non-exclusive, worldwide, royalty-free, sublicensable, transferable right and license to use, host, store, cache, reproduce, publish, display (publicly or otherwise), perform (publicly or otherwise), distribute, transmit, modify, adapt (including, without limitation, in order to conform it to the requirements of any networks, devices, services, or media through which the Services are available), and create derivative works of, such Subscriber Content. The rights you grant in this license are for the limited purposes of allowing Tumblr to operate the Services in accordance with their functionality, improve the Services, and develop new Services. The reference in this license to “creat[ing] derivative works” is not intended to give Tumblr a right to make substantive editorial changes or derivations, but does, for example, enable “reblogging,” which allows Tumblr Subscribers to redistribute Subscriber Content from one Tumblr blog to another in a manner that allows them to add their own text or other Content before or after your Subscriber Content.
You also agree that this license includes the right for Tumblr to make all publicly-posted Content available to third parties selected by Tumblr, so other media and services.
Note also that this license to your Subscriber Content continues even if you stop using the Services, primarily because of the social nature of Content shared through Tumblr’s Services - when you post something publicly, others may choose to comment on it, making your Content part of a censoring the speech of others.
You also agree that you will respect the intellectual property rights of others, and represent and warrant that you have all of the necessary rights to grant us this license for all Subscriber Content you transfer to us.