Greater lens versatility. Several manufacturers' SLR lens systems offer more than 40 lenses, each optimized for its intended purpose. Sample from a smorgasbord of zooms, ultra-wide-angles, supertelephotos, and specialty optics such as macro and perspective-control lenses.
Almost always better image quality at a given resolution. In other words, 10 megapixels from a digital SLR beats 10 megapixels from a typical digicam. This advantage is especially dramatic at higher light sensitivities (ISO 400 and greater).
Better performance. Typically, digital SLRs have faster autofocus, shorter shutter delay, faster continuous shooting, and a bigger memory buffer.
Usually a more functional "shooter's" design. Some designs are better than others, but digital SLRs tend to have easily accessible thumb and forefinger wheels for exposure settings, discrete buttons for other critical features (exposure compensation, white balance), vertical position shutter releases, and just less menu surfing overall.
Greater flexibility. Access to a much broader range of accessories, including powerful external flashes, alternate power sources, wireless transmitters, and remote triggering devices.
Disadvantages of the Digital SLR Camera:
Generally bigger and heavier. The SLR mirror box and pentaprism add some weight and bulk compared to a point-and-shoot's design. Other factors include heavier, more durable materials and the need for larger batteries to power higher-performance components. That said, many recent entry-level models are about as light and compact as the larger EVF cameras.
Increased complexity. Choosing and changing lenses while shooting is an unwelcome chore for some folks. Plus, digital SLRs generally have a plethora of buttons and dials, which can intimidate some users.
Higher prices. While the least-expensive digital SLRs are now available at prices that compete with non-SLR cameras, the price range for digital SLRs is generally higher.
Generally inconvenient to use the LCD for framing. The introduction of Live View mode has made it possible to frame with a dSLR the way you do with a point-and-shoot model, but because dSLRs are signficantly bigger and heavier than your typical snapshot camera, and not really designed to be held at a distance in front of you, the process can be a bit awkward.
We are by now painfully aware of the cost difference between film and digital, but very little is discussed about the loss of highlight detail (try photographing cotton wool or white flowers???). The massive array of monitor, printer, camera calibrations and generally people don't know much about calibration or attempt to use profiles. There seems to be and endless amount of costly solutions to be applied to something that by now should be perfectly simple. Lets not forget the amount of storage media we buy and can't find when we need it, and the constant built in obsolesance, its like being stuck in a computer nightmare. Please don't get me started on Photoshop and and an army of file interpretation software and the half assed so-called EXPERTS spoon feeding kindergarden show and tells in $25 Photoshop magazines that are actually 75% advertorials. God help us.