Fujifilm Real 3D W3 has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features 3D RP(Real Photo) HD processor. On the other hand, Panasonic XS1 has a
16.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Panasonic XS1's sensor provides 6MP more than Fujifilm Real 3D W3'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 Real 3D W3 and XS1 sensor size comparison.
Fujifilm Real 3D W3 and Panasonic XS1 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.