How is this going, whats happenend to the widget?

No-one has stepped up to port it.

For some reason the original code is on launchpad: https://launchpad.net/plasma-widget-menubar (no idea why) if someone wants to do it.

And the rest except the widget?

The rest is being built as part of plasma-workspace. I'm not sure how much testing it has had.

Afaics the widget has been discontinued, because canonical jumped out of abusing dbusmenu-qt and into something else, so it (as well as a probalby a Qt plugin to feed it) would have to be written from scratch.