The Sony Cyber-shot DSC-TX1 and DSC-WX1 are both 10-megapixel cameras, which in and of itself is not that impressive. What is impressive is the back-illuminated CMOS sensor, the Exmor R, that they use. The sensor is based on those found in Sony digital SLRs and promises to deliver improved low-light performance without help from a flash or tripod. According to Sony, the new design has "approximately twice the sensitivity compared to conventional sensors."
Both cameras incorporate the hand-held twilight and antimotion blur multishot modes introduced in the Cyber-shot DSC-HX1. They also get that model's sweeping panorama shooting capabilities. However, that thing is a large, 20x megazoom camera, whereas these are very much not. The TX1--like all of the T-series models--is a very thin camera at 0.7-inch thick and has few physical controls, instead relying on a revamped 3-inch touch-screen interface. The WX1 is only slightly thicker at 0.8 inch.
So the TX1 has its small body and touch-screen LCD going for it, but its lens specifications are less impressive than those of WX1. It is folded inside the body, which is nice, but it's a 4x f3.5-4.6 35-140mm-equivalent lens; the WX1 has a 5x f2.4-7.1 24-120mm-equivalent lens. At f2.4 you'll get a lot more light in, further improving its performance in dim lighting. Plus, 24mm is considerably wider than 35mm. You'll have to decide what's more important--portability and a flashy design and interface or shooting flexibility and $30.
The TX1 camera will come in silver, gray, pink, and blue this September for about $380. The WX1 camera will be available in black this October for about $350.