A comment "cgpetroski" on the Panasonic Lumix DMC-FX580 / DMC-FX550 at Amazon sheds some light on the touch screen feature:
I was worried that the touch-screen control of many functions might be just a gimmick. It isn't, and I am especially impressed at what the AFAE (Auto-Focus Auto-Exposure) function does: When you activate it, it tells you to touch whatever you want the AFAE to work on. The thing or person doesn't have to be in the center of the screen. It's like magic, as you watch the change in focus and the correction of the spot-metered exposure happen. It blows me away.
DigitalCameraInfo.com's First Impressions of the Panasonic Lumix DMC-FX580 Digital Camera Review adds:
Aperture priority, shutter priority, and manual exposure mode each allow for a varying amount of manual control. Unfortunately you must use the LCD touchscreen to fine-tune both aperture and shutter speed manually. The camera cannot perform a manual focus.
The FX580 / FX550 certainly has impressive amounts of manual controls for a compact digital camera.