With todays digital cameras, the imaging ccd is simply getting better and better. This helps in producing smaller and better ccd's. This, in turn, produces smaller and better cameras. The one area that the P&S cameras lack is the lens. There are some out there that are VERY good though. You will pay a higher price for them. Panasonic has a very nice P&S with a very nice lens. Unfortunately, you will simply be limited by being forced to use the lens on the camera. Yes, there are the attachments, but they don't come close to having a lens designed to take the particular photo you want.
The DSLR's, though more pricey than P&S cameras, offer the ability to expand beyond the kit lens. With the DSLR of today, the imaging ccd's are better than they were a few short years ago and have surpassed 35mm film in their resolution. This makes the body of the camera more of a transport as we saw with the 35mm film camera bodies. You will have to make a choice though as the camera body still has a lots of image processing to do. Much more than film bodies ever did.
The Lens is key to the photo. The quality and style of the lens simply makes or breaks a perfectly good photo. A lot depends on how anal you are about your photos as to the quality of lens you will buy. Buy the BEST you can afford. SAVE for better later.
Whether you choose Canon, Nikon, Minolta, Olympus, Sigma, or Pentax is really a personal choice. Every last one of them will produce excellent photos in capable hands. Learn everything you can about photography. There are several excellent web sites dedicated to Landscape and Nature photography and the wealth of information is overwhelming at times. Learn to use your equipment, then Use your equipment to learn photography.
