Toshiba Satellite users have reported, on various forums, miscellaneous issues related to LCD screens, but Toshiba has never issued a screen recall and has only had one support notification related to its displays.
Toshiba's only support bulletin related to its Satellite laptop series affects the Satellite A210, Pro A210 and P200D models. On these systems, the LCD screen will occasionally go blank. The issue is fixed with a BIOS update, which is downloadable from Toshiba's support site.
Toshiba's specification documents for the Satellite series laptops warn users the screen will have problems over time. According to Toshiba, the screen's backlight will lose power over time, depending on how frequently the system is used. The document doesn't specify how long the screen will last, nor can it. Think of your LCD screen on the laptop as a television set; it doesn't last forever, but any unusual dimness -- especially when the system is new -- should be considered a malfunction.
Newer Toshiba Satellite models use thin-film transistor technology to enhance the display. As a disclaimer, Toshiba notes that bright dots may appear on the screen when the PC is first booted up as a part of the TFT display. This is normal behaviour for your PC.