Output pixels, real measure of a digicam performance?

I'm a regular medium format shooter, but lately I've been tempted to
go digital for online sharing and documental purposes. Not having paid
attention to digital camera development for some time now, I'm
suddenly amazed by the amount of cheap 2 mega pixel cameras going
around. Currently I use a Yashica T4 for this kind of pictures, but
I've found I never enlarge the amount the lens or film can give, but
have to live with film inherent drawbacks. I have tons of questions,
but I remember there were some comprehensive permanent sections on
photo.net about the image pixel size vs. enlarging capabilities. I'd
thank anyone for providing info on this. But there's deeper doubt.
I've seen great 1200x1600 images, and ugly ones in the same size. I
know I can expect a very nice scan from a good original at that size
with a cheap scanner. What should one expect from a digicam that
outputs a similar image size? What about noise or smoothness in color
variations? This questions are important to me because the smoother
the picture is, the easier to apply enlarging software like genuine
fractals, or sharpening, etc, if wanted. In short, is image pixel size
a reliable measure to say a group of cameras that produce 2mp images
similar in image quality? I believe if an image has noisy color or
color changes, post editing will mess it up completely. Any comments?
By the way, I found the new Olympus D-390 (a Stylus look alike?) very
attractive for these simple purposes, any thoughts on this one? I
shoot mostly Velvia in 6x9 format, that's obviously not what I'm
asking from the digicam, I'm far from wealthy enough to get that kind
of digital. Thanks for any ideas.

 

For the same number of pixels, you should be better off with a digital photo
than with a scan from a print. A print has limited color depth, and any
imperfections in the printing process will be present in the scan. Scanning
a negative will work better, but not necessarily better than a photo from a
digicam.

What about noise or smoothness in color

Noise can be present in film too. And color smoothness is a matter of color
depth, or too much jpg ocmpression can cause poor color smoothness. To get
a sense for the effect of color depth, pull up a picture with lots of blue
sky on oyur monitor, then reduce the color depth of the monitor.

This questions are important to me because the smoother

No amount of photo editing can increase the detail in the image. However,
image editing can make a picture look better in other ways.

A 2Mp camera can take nice snapshots. The Oly D-390 has a fixed lens. That
is a serious drawback. There is a reason for the low price.