Plone 4.0 is a new major release of Plone, which builds on the Plone 3 release series. Substantial speed improvements, smaller RAM footprint, better support for large data volumes.
Plone 4 will focus on updates in the underlying Zope and Python technologies, substantial speed improvements, better support for large data volumes, and a variety of end-user features.
A final release is to be expected in early 2010.
Improvement proposals included in this release:
#7822 Make standard file content types use ZODB BLOB support
#8801 Move action icon support into actions, deprecate CMFActionIcons
#8802 Move our upgrade / migration infrastructure to GenericSetup
#8808 Require Python 2.5 or 2.6, Zope 2.12, and CMF 2.2 for Plone 4.0
#8814 Replace SecureMailHost with a standard Zope mailhost
#8815 Use normal CSS and no more magic base_properties
#9186 Set Image IDs from Title field
#9214 support logins using e-mail address instead of user id
#9249 Add TinyMCE as the default visual editor
#9250 Add jQuery Tools to base install
#9256 Expand variable substitution in mailing action of plone.app.contentrules
#9258 Replace Products.ATReferenceBrowserWidget with archetypes.referencebrowserwidget
#9259 Group dashboards
#9263 GenericSetup syntax for importing Sharing page roles
#9264 Merge backport patches from plone.app.dexterity into Plone
#9272 Exposing and editing Dublin Core properties
#9285 Show blocked portlets in management interface
#9286 Allow to show/hide portlets
#9305 Use real names instead of usernames
#9309 Better search for East Asian (multi-byte) languages.
#9310 User registration process more flexible
#9315 New theme for Plone 4
#9316 Unify folder implementations
#9321 Reimplement the search form with an eye on usability
#9330 Add ability to choose group when adding new site members