Why can't a non-SLR have equivalent quality?

[Prime]

I've been waiting and wondering when we will see this.

I'm personally tired of carrying big cameras. I've got a great point and
shoot 7mp. I would like some more lens flexibility but don't want to be
burdened down by a SLR. I used a film SLR but found the size differential
of a good point and shoot (for me) was too valuable to ignore.

For example, I really like the Panasonic FZ5 - Leica lens, very small, 12x
optical+ stabilized zoom. I almost bought the camera. Yet when I look at
sample photos the 5mp sensor has noticable noise, even compared to my Sony
DSC-P200.

When and why don't we see a 6-8mp prosumer camera with an image sensor
equivalent to one in a digital SLR? I would expect a major market for such
a camera. Perhaps bigger than the smaller point and shoot cameras, but
still a lot smaller than SLRs. And you wouldn't worry about dust on the
sensor!

[Leo]

Larger sensor requires larger, more expensive lenses. The fact is the
current P&S's are good enough for the general public when use under
optimal lighting condition. I wouldn't see the manufacturers want to
sacrifice price and size for the mass market products.

[Frederick]

When a zlr can have an electronic viewfinder that displays at least
close to the full 8mp at 25fps with no (as in practically zero) delay,
then a large sensor zlr makes sense. I'd buy one. The mirror on an slr
is just an necessary evil - noisy, delicate, destined to fail in the
end, and probably a significant cost component of a dslr.

[Skip]

Compare the Canon Rebel XT/350D to the Olympus C-8080. Both are 8mp
cameras, the Canon an SLR, the Oly a ZLR, and the Canon is lighter and
smaller in a couple of dimensions, and is only marginally larger and heavier
than the Panasonic you mention. Of course, add a lens and that changes
somewhat.

[David]

Canon 350D - 540g
Panasonic FZ5 - 326g

540g vs. 326g is marginal? It's 65% heavier. Now add Canon EF 75-300mm
f4-5.6 USM image stabilised lens: 650g, making 1190g.

It's great that those of us who do not wish to lug 1.2kg around all day
have the choice of the much lighter system, and that those who want the
better high-ISO performance have that option as well.