HAHA. A complete checkout of WebKit takes so long, that there are two new commits in the meantime:
$ svn checkout http://svn.webkit.org/repository/webkit/trunk WebKit
…
U WebKit
Checked out revision 48716.
$ WebKit/WebKitTools/Scripts/update-webkit
Updating OpenSource
U WebCore/ChangeLog
U WebCore/inspector/InspectorFrontend.cpp
U WebCore/inspector/front-end/ConsoleView.js
U WebCore/inspector/front-end/WatchExpressionsSidebarPane.js
U WebCore/inspector/front-end/inspector.css
U WebCore/inspector/front-end/InjectedScript.js
Updated to revision 48718.
They should switch to git.