Ever since Apple's PowerBook line met its end last year, people have been clamoring for Apple to return to them a 12-inch laptop. Rumors of Steve Jobs granting their wishes and bestowing upon them an ultraportable, professional-grade notebook have been fairly consistent since the man introduced the 15- and 17-inch MacBook Pros. Today, MacScoop quotes "trusted sources" that point to the arrival of a 12-inch MacBook Pro by the end of the year. These sources say the laptop will be half as thick as the old 12-inch PowerBook at 0.6 or 0.7 inch (15 to 18 millimeters to our international readers). This rumored laptop will weigh less than 3 pounds, making it the lightest Apple laptop ever released. If it's ever released.