Repeat this 100 times: "It isn't the camera, its the photographer."
Memorize this: "Pictures are not taken, they are made." Ansel Adams.
The photographs that so impress you were made by a person knowledgeable about light, composition, exposure and depth of field and with the skill to use that knowledge to make impressive photographs. The camera they used is just a tool, like a hammer or socket wrench or saw.
I used a 1970s vintage Minolta XE-7 with an equally vintage 200mm lens to make this picture a couple of weeks ago: http://www.flickr.com/photos/drifter45h/4048796836/ Do you think it would have been "better" if I'd used a Canon or Nikon DSLR? How about this one? Same camera, 21mm lens:
http://www.flickr.com/photos/drifter45h/3991210245/
Please note that I do not expect you to be impressed by either photograph. I used them to illustrate my point that a camera is just a tool. I used another tool - my FotoSharp "Day & Night Exposure Guide" for "Galt House Hotels". For "Bench-Trees-Lake Nevin"I used my knowledge of depth of field for the lens used. 21mm, f16, focused at 6' and I know my depth of field is from 2'-2'' to infinity. My tripod and cable release were additional tools I used for both pictures.
So if you have no knowledge of light, composition, exposure and depth of field the camera you buy is pretty much irrelevant.
Buy the camera that feels the best in your hands. Then begin studying about light, composition, exposure and depth of field. Here are some sites that will help you:
http://www.digital-photography-school.com Tutorials suitable for the beginner to the professional.
http://www.dofmaster.com/dofjs.html Good explanation of Depth of Field (DOF) and a handy DOF Calculator you can use to compute DOF for any combination of lens focal length, f-stop and subject distance imaginable. (Those are the only factors that affect DOF - lens focal length, f-stop and subject distance)
http://www.calculator.org/exposure.aspx By using the various Scenes listed you can begin to learn how ISO and f-stop affect shutter speed - and why you'll want a 50mm f1.4 lens for low-light photography when you don't want to use the flash.
http://www.illustratedphotography.com/photography-tips/basic
These books will also help you in your journey:
"Understanding Exposure", "Understanding Shutter Speed" and "Understanding Photography Field Guide" all by Bryan Peterson.
Plan on spending a lot of time actually READING & STUDYING the Owner's Manual for your new camera.
Once you begin using your new camera, don't think you are learning anything by taking hundreds of pictures. Remember the Adams quote? The idea is to make a picture, not take a snapshot. Good photography requires thinking - thinking about exposure, composition, light, depth of field. If all you do is point & shoot, point & shoot, point & shoot then you obviously aren't thinking. Taking 300 lousy pictures teaches you how to take 300 lousy pictures. Making 20 to 30 good photographs shows that you are thinking and using your knowledge of light, exposure, composition and depth of field.
Always strive to "Get it right in the camera" and you'll spend less time in post-processing and more time with your camera.