Product Previews palmOneUpgrades Treo With Faster Chip, Better Display\With more than 600,000 units shipped, the Treo 600 is one of the big smartphone success stories. Last week, palmOne introduced the follow-on Treo 650 with a higher resolution 320-by-320-pixel TFT screen, which the company claims increases the visible area of the display and makes pictures and documents much clearer. The 650 also carries a removable battery; 32MB of flash memory, and a faster 312MHz, Intel XScale processor. Improved multimedia features include a built-in MP3 player, a digital camera with improved low-light capabilities, as well as video capture and playback functionality. Products are expected to ship by years end from some carriers who will add their own services, and will be priced at about \$499.\ Treo 650, palmOne