If we define "prosumer" cameras as those with 5x lenses and higher (including the 12x Panasonic Lumix FZ-20), then in the past year we've seen the "prosumer" category split into two distinct groups: those that favor the very-wide-angle (28mm "equivalent" or wider), and those that favor the moderate wide-angle. Consumercams of yore, including the permanent-mount 35s and most zoom-equipped digicams since the beginning, zoom-out to a wide-angle extreme whose "equivalent" is 35mm. As far as wide-angle lenses go, that's not very.
The wide-angle end of things is still the province of the interchangeable-lens DSLR. Those 2x 17-35mm lenses mentioned earlier provide about a 24mm "equivalent" wide-angle view, which is substantially more than the 28mm of the permanent-lens models. Nikon and Sigma both have introduced 12-24mm lenses (the Sigma model providing full-frame coverage, bestowing a true 12mm on the three full-frame cameras now selling—two Kodak DSLRs and a Canon, prices starting at about $5k). Some of these interchangeable-lens DSLRs are beginning to penetrate the prosumercam's price range, even as the prosumercams have penetrated the DSLR's extravagant versatility.
X Marks the Spot
The interchangeable-lens cameras and permanent-lens prosumercams have, in fact, begun a crossover that we should expect to turn into a landslide. At the time this is written (mid-January), the best deal we find on eBay for a 6.3MP Pentax *ist DS with standard 18-55mm lens, brand new, Pentax USA warrantee, is $869; for the 6.3MP Digital Rebel with standard 18-55mm lens, $849; for the 8.1MP Olympus E-300 Evolt with standard lens, $829. This is around what we paid for the Kodak DC50 in 1996, and half the price of the Ricoh RDC-1.
It's also what you pay, more or less, for many of the 5x-and-higher, 5MP-and-more, fixed-lens prosumercams described here. Within a range of $100 higher or lower, Joe 'n Jane Foto can consider three breeds of prosumercams where there were once only two: wide-angle specialists, telephoto specialists, and interchangeable-lens DSLRs that specialize in everything.
Now that the vast economic distinctions between fixed-lens and interchangeable-lens cameras are disappearing, the complexities of buying—and selling—these products compound. It's easy enough to figure out if you need a fixed-lens camera whose strength is wide-angle or telephoto. But how do you compare that decision against the prospect of buying a camera whose interchangeable lenses can cover the same range?
A few of the pros and cons:
Permanent-lens cameras are more compact, and their mounts, being permanent, cannot be knocked out of alignment or otherwise damaged. But interchangeable-lens cameras still have physically larger imaging chips (in most cases) with larger pixels, so theoretically are capable of a cleaner, lower-noise picture.
Don Sutherland has sold cameras across the counter, shot with them as a pro, and written about them for more than 30 years. His first article predicting the future of digital photography (1976) is becoming truer and truer. Don is a photo historian as well as futurist, and is author of the immortal slogan, "If you have one foot in the future and one in the past, you understand the present perfectly." Email Don at firstname.lastname@example.org.
You usually don't require cleaning the imager in fixed-lens cameras. You do in interchangeable-lens cameras (except for the Olympus models, with their supersonic wave sensor-cleaning feature).
Interchangeable-lens DSLRs have bright, color-accurate optical viewfinders. Fixed-lens cameras have electronic viewfinders—better than they used to be, but still like watching your pictures on TV.
Fixed-lens cameras have pivoting LCDs, interchangeable-lens DSLRs don't.
DSLRs are probably faster-handling, though that gap is closing.
Everything is changing as prices come down, and the once clear-cut is starting to blur. It should be an interesting year, as Joe 'n Jane Foto come in with their new sets of questions.