I've said this before and I'll say it again now...don't just look at the megapixel count but pay close attention to the sensor size (physical dimensions). The primary difference between the image quality of a point'n'shoot versus a DSLR isn't the pixel count. My wife's little Nikon Coolpix has the same nominal pixel count (10 meg) as my Nikon D200 DSLR. However, there is at least a 2:1 difference in linear dimension (4:1 diff in area) between the sensors. Our ability to lay down features on silicon is a whole lot better than our ability to focus visible light onto said sensor, at least with reasonably-affordable glass. Her Coolpix has a tiny little zoom lens, not the big honkin' 12~24 and 24~120 zooms that I carry with the D200. If you figure on the 16x24mm DX sensor in the D200, it has about 2500x4000 pixels (I'm rounding to make the math easier), which says about 150 pixels per millimeter. In order to use all of those pixels, my glass has to throw an image with at least 75 line pairs/mm onto the sensor. Some of the best glass Nikon has ever made (fixed-focal-length lenses, not zooms) would hit 100 lp/mm at their optimal aperture, so the D200 is already at or just beyond the limit for what my good zooms will do. When you shrink the imager to something like the Coolpix has, you'd need lenses capable of laying down 300-400 lp/mm to actually use all those pixels, so in a point'n'shoot, no way will it matter whether you have "only" 6 megapix, 10, 12 or 20...your image quality is limited by the imager SIZE and the glass in front of it. T'other thing is in sensitivity...the larger pixel size in the D200 lets it capture more photons per pixel at a given exposure, so the sensitivity is higher and imager (electronic) noise is significantly lower, especially if you run the ISO setting up under dim lighting conditions.
That said, I really like the NEX3/5/7 line from Sony. Same imager SIZE as my D200 but a whole lot lilghter and if you are willing to hike with just the 16mm "pancake" wideangle, it's a very compact unit. The 18~55 zoom is a bit of a honker but the rig is still a lot lighter than my D200. I'm seriously considering an NEX-7 at some point, especially if I get back into underwater photography as well as mountain stuff...takes a lot less bulky housing to dive with an NEX-7 than a D200!
If you want to compare different cameras in the hands of the same photographer, take a look through the "highpointing" and "travel" sections of my
web site. The stuff from Huyna Picchu (travels) and the highpointing trips from 2001 - 2004 were shot with a 3-megapixel Nikon 990 or 4-megapixel Nikon 4500. Stuff after 2006 or so was shot with the D200.
While we're on the subject, the other primary question to ask is, "how do I want to use the images?" If you're like my wife and take your flash card to the local one-hour photo kiosk for 4x6 prints, a point'n'shoot will be more than good enough. If you're using them for web publishing, ditto...even a "high definition" monitor may be 1920x1080 pixels or about 2 megapixels, so your source images are still a factor of two to five better than anybody can look at, full-screen. However, if you're after pro-quality 8x10 or larger prints, you need the larger imager size and will need at least something like an NEX3/5/7 or a DSLR. (Figure at 300 points per inch on the paper an 8x10 is 2400x3000 pixels or about 7 megpixels. With my old 3-meg Nikon 990, I could just barely get a clear 8x10 out of it if I could use every pixel in the original image and didn't have to crop very much. It's a lot easier with the D200...)
Getting off my soapbox now...splinters hurt my toes...
