For those who care - I think the Ultraview is Yokogawa's Nipkow disk system.
We've used it and been quite impressed by its performance. As far as speed
goes, they can spin the disk at a variety of speeds (factory option) so that
one can go up to 1 khz on the imaging end and not get "striping" effects
from incomplete scanning with the disk. This system is selling well in Japan
because of its ease of use - basically it just attaches to the photo-port of
your microscope. Put a camera on the output and you have and real-time,
direct view confocal. Definitely one of the simplest units available (the
Meridian unit fell in this category as well).
It's well worth a look.

What this technology will NOT buy you are some of the features of the
conventional, point scanning confocal. These include:
1) variable pinhole size - holes are fixed in the spinning disk. Hence the
scope is confocal optimized for a single objective. It works fine for a
variety of objectives, but your best Z and out of focus rejection comes with
a specific objective.
2) line scanning - the disk systems always scan a full image.
3) flexible multi-wavelength support - last I knew, they were working on
multiple wavelength support so you could do something like FITC, RHOD, DAPI,
but I've never seen this in operation on this scope. However, my
understanding is that when it is supported, it will be via a
multi-wavelength cube. The advantage to this is that you can then see a true
color resultant image live. The disadvantage is that if you put a nice high
res monochrome CCD on it, you'll get all the wavelengths simultaneously
unless you put filters in front of the camera.

This all being said - I would say that this type of system should be placed
in a different category from the conventional point scanning confocal. While
tempting, one shouldn't really look for "the ultimate confocal" - one that
can go fast as well as give the ultimate images and flexibility. This is no
different than shopping for automobiles - do you want a pick up truck or a
Porche? You wouldn't criticize the Porche for not being good off road or for
inability to haul your firewood. Likewise, you wouldn't mind if your truck
did 0-60 in 10 seconds! Decide on your main application and determine which
device is optimal.
One can make up a "decision tree" to help with this. If people are
interested, I can write up an article that walks through these steps to help
one decide on the most appropriate technology based on a set of needs.
-Ted Inoue