Methods

Containment *containmentForScreen(int screen, int desktop = -1) const; Remove desktop?
Containment *containmentForScreen(int screen, int desktop, const QString &defaultPluginIfNonExistent, const QVariantList &defaultArgs = QVariantList()); Remove desktop?

Still necassary?

void setAppletMimeType(const QString &mimetype);
QString appletMimeType();
void setDialogManager(AbstractDialogManager *manager); DialogManager was fow main windows of config uis. If all config is going to be qml, this could go (alternative is that we do an AbstractDialogManager that is a declarative view: possible as well).
AbstractDialogManager *dialogManager();
QString preferredToolBoxPlugin(const Containment::Type type) const; Toolboxes, instead of plugin may come from the only corona QML package.

void setPreferredToolBoxPlugin(const Containment::Type type, const QString &plugin);

void setDefaultContainmentPlugin(const QString &name); Default containment plugin also told in the one Corona QML package?
void requestConfigSync(); Ugly api: are requestConfigSync and requireConfigSync still required both?
void requireConfigSync();

Signals