GWT 2.8.2 erschienen

Supports running in Java 9. Note that this does not yet mean that GWT can compile Java 9 sources, or support the Java 9 JRE changes, but that a Java 9 JRE can be used to compile a GWT project. Do note that the new --module-path flag is not supported, but-classpath must still be used as in the past.
Chrome 61 removed functionality that had been used for reading the absolute top/left values. The internal implementation has been updated to reflect modern standards.
Uncaught exception handler will now receive all errors on the page, as handled bywindow.onerror. This may potentially be a breaking change if there were misbehaving scripts on the page. To disable this functionality, set the propertygwt.uncaughtexceptionhandler.windowonerror to IGNORE:

For more details, see com.google.gwt.core.Core.

LookupMethodCreator creates too large method
NativeRegExp should use iframe instance, fixing Edge JIT bug
JsProperty getter/setter sometimes were reported as incompatible
Instantiating native JsTypes from JSNI results in InternalCompilerException
Remove the SUBSIZED characteristic from filtered streams
Internal compiler exception when using native JsType varargs in a JsMethod
Regression in String.toLowerCase and toUpperCase for some locales, specifically for Turkish
Missing bounds check in String.charAt
Fix AIOOBE when compiling method references involving varargs.
Apply HtmlUnit workaround ensuring that window.onerror is called correctly

Migrated lang/jre emulation JSNI to JsInterop to share with J2CL
Added ErrorProne to gwt builds
Improved compliance with CSP
Added emulation for java.io.Externalizable
Added emulation for java.lang.reflect.Array
JSO.equals/hashcode will delegate to the JS object if it has methods with those names
Removed outdated or unused parts of project
Migrate guava JRE emulation to GWT
HtmlUnit tests are now run in batch mode

For more detail, see the issue tracker and the commit log.