Now that I have the firmware for it in my camera and I see it on sale at B&H and Amazon, has anyone used this lens yet? Are the power zooms clean and provide stabile focus during the zoom?

Looks real nice. OIS would be wonderful to have.

I have a theater shoot tomorrow where this lens would be great to have and B & H is a mile away (although it's a rough place to be in sometimes). I might just go later and see if they have a floor model to play with.

A video posted by Panasonic. Very nice looking however the zooms are modest and done in bright sunlight so the focus could be stabile due to wide DOF. Hard to tell.
Actual Video Sample of LUMIX G X VARIO PZ 45-175mm / F4.0-5.6 ASPH. / POWER O.I.S. - YouTube (http://youtu.be/1eqIzlA-h6c)

This is a short video of a ferris wheel in daylight somewhere. The camera zooms in out of focus, focuses and then zooms out and seems to hold focus.
Panasonic LUMIX G X Vario PZ 45-175mm F4-5.6 POWER O.I.S. - YouTube (http://youtu.be/BfvDBYTw2tM)

A night street scene. The camera seems to be in auto focus but may not be. The lens zooms in, focuses, zooms out and goes out of focus. It focus on the wide shot, zooms in and goes out of focus.
????G X VARIO PZ 45-175mm?1920x1080?60i?night?movie - YouTube (http://youtu.be/QpfZ5BQ-tqs)

Not a definitive set of video tests. I did not get to B&H yet, too busy.