A good bridge camera is one that allows for the user to grow and stretch into a deeper understanding of their craft. It should have the functionality to control light through ISO, aperture and shutter speed. It should have instant shutter release (you push the button and it goes!) and a hot shoe (for flash).

I suggest a hot shoe because built in pop-up flashes are really good for two things: triggering other strobes (good thing) and washing your subject in a nuclear blast of FOC (Flash On Camera, bad thing). As the hobbyist gains confidence and skill, they will want to create more dramatic and balanced images with an off camera strobe of some sort, and thus will need a hot shoe mount on their camera.

Other than these basics, the truth is Nikon, Canon, Panasonic and Sony all have banging models with tons of groovy gadgets. The extras are just that, extras, and most of what they offer you'll never ever use. I know you're shopping for your brother, but think about ergonomics. What feels right? Can you change lenses?

For my vote, I've talked several friends into the Nikon Coolpix P100. Huge CMOS chip. Fast shutter. HD Movie. Gorgeous body. Classic Nikon durability. AND the controls feel more like a true SLR, so your fingers begin to learn what is required of them in high speed, high stress situations. It is my favorite.