Yes, there is going to be one with a backlight screen. Nintendo didn't do it originally to keep costs down, and to keep power consumption low. (They are only allowing this one because it is apparently now possible to have a backlight with only 10% more power usage.)
Even better is the GBA docking station for the GC coming in the late winter/ early spring. You'll be able to play GBA games through the GC on a TV. (Without modifying it like the kit that is available now.)