Choosing still cameras for dual use

Like many other people I am interested in choosing a digital camera or
two for dual use. i.e. astrophotographs and terrestrial photographs as
well. Is there somewhere I can go to collect that sort of education?

It appears relatively clear that the Canon 10D, 20D and Digital Rebel
would meet that need. The Digital Rebel is more or less affordable.

However, as a fellow with a fair bit of moderately expensive Nikon
glass, I am interested in whether the Nikon D-70 is capable of decent
astrophotography. At least a few people must have tried it already.

Also, there are now a bunch of 6+ megapixel reflex-type non-removable-
lens digital cameras available. Is there some way to find out about
their suitability for afocal use or for direct use for wide-field shots
without a telescope? I can handle the trivial stuff like long-exposure
capability and remote-triggering and such but I am lost in terms of
detector sensitivity, noise, optical "bandpass" in terms of chip +
filters + electronics and such?

I do not yet know enough about this to ask the questions more
intelligently. My apologies and my thanks for any help.

- Shankar