P&S cameras are getting faster, and increasing HIGH-iso performance – case in point, Canon’s S90.   EVIL (Electronic Viewfinder Interchangeable Lens) cameras are coming on strong (i.e. Panasonics’ GF-1) but are still very price with smaller lens selection.  So for the time being at least DSLRs do have advantages – here are a few DSLR Advantages:

• Fast- from cold start to picture taking DSLRs are king and time is measured in milliseconds.  And fast from shot to shot, many DSLRS can take several high quality images in less than a second.
• Battery life is exceptional in most DSLRs with numbers between 500-1000 depending on flash use. A good P&S approaches 300ish
• A control scheme that lets you change common settings without wading through menus. I am comfortable enough to change most of my commons settings by touch alone because the buttons are smartly placed and work well.
• Interchangeable lenses allows your camera to specialize in any type of photography- going from exceptional wide angle to incredible macro if you have the lenses.
• High ISO performance, this means that in low light you can take clear crisp pictures without a ton of grain(noise).
• External Flash – The ability to add an external flash to your setup can do more for your pictures than any other accessory including lenses.
• Complete manual control including hour long shutter length if desired.

DSLR disadvantages:

• Bulky/heavy, DSLRs are large, often heavy and will not fit in a pocket or even a small purse
• They are hard to hide, related to the above, and scream “look at my camera, steal my camera”
• Lenses can be as, or even more, expensive than the original camera
• You can get dust on the sensor, or in the lenses, this has been better addressed in recent bodies though

I have a DSLR recommendation guide and a P&S recommendation list