[bojan]

Fahim, I can see your point too :-)
However, I found that I do not need to focus that often, once per evening is enough of course. Actually as I have dedicated lens for wide angle ( 135mm and 200mm) I fixed the focus ring and that's it, I do not need to re-focus ever again... I am checking from time to time but it never changes enough to justify the re-focusing.
I never tried Russian Focus confirm chip, but I tried Chinese one and it is not very reliable (something is intermittent, it does not communicate with camera reliably. But when it works, it works on brighter stars, and with faster lenses (F5.6 and more. Not much luck with slower optics, though). FocussAssist is, however, the tool I am using (when I am re-focusing, that is).

EDIT:
Autofocus (and focus assist chips) work with shutter closed, actually, and all they do is they make camera "think" the proper autofocus lens (in manual mode) is attached to it. There is a small secondary mirror (behind a main one) that projects the image downwards where the focus assist CCD array is mounted. So everything is happening without live view..
I do not know for sure but I imagine that with cameras equipped with live view, autofocus will work via main sensor as well (when shutter is open)