Sony S2000 has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Bionz processor. On the other hand, Sony WX150 has a
18.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features BIONZ processor.
Sony WX150's sensor provides 8MP more than Sony S2000's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the S2000 and WX150 sensor size comparison.
Sony S2000 and Sony WX150 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Sony S2000 has 100% larger pixel area compared to Sony WX150, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.