The most important new feature is the possibility of showing the delete action to all the items displayed in the list view, which was a feature requested by lots of users. When upgrading to the new version, keep in mind that when defining custom CSS classes for entity properties, you must use the css_class option and not the deprecated class option (this was deprecated a while ago, but because of a bug it wasn't enforced until this version).
New features
[0a85143] Allowed to add the delete action for all the items displayed in the list view (@ogizanagi)
[49a0057] Introduced AdminController::getEntityFormOptions() to allow setting form options before sending it to the form builder (@Pierstoval)
[0d80068] When no configuraiton is defined, we exclude some fields by default to improve "the first experience" (@javiereguiluz)
[a940b8a] Allowed to use a custom template for exception pages (just override the exception.html.twig template using the same mechanism applied to any other template) (@javiereguiluz)
Bug fixes
[239c1fe] Properties must define css_class instead of class in their configuration (@ogizanagi)
[a094064] Fixed ExceptionListener: exception to log isn't necessarily a BaseException instance (@ogizanagi)
[2119850] Fixed virtual field should not have a default label (@ogizanagi)
[7cb121b] Allowed to use 'horizontal' and 'vertical' form theme shortcuts even when using several form themes simultaneously (@Pierstoval)
[e4188bf] Fixed the CSS class applied to form-group <div> by using block prefixes (@ogizanagi)
Documentation
[ffc5d35] Added a new tutorial about integrating VichUploaderBundle to allow file uploading (@javiereguiluz)
[beb67f7] Added a new tutorial about translating the backend (@javiereguiluz)
[dd409de] Added a new tutorial about defining custom actions (@javiereguiluz)
Misc. changes
[65998b4] Refactored the EasyAdminExtension DI extension (@javiereguiluz)
[35b3576] Updated the Spanish translation file for form.label.empty_value key (@sebastianlp)