The notebook design is dramatically simplified and the graphics unit needs less valuable space. Soon we will see shared memory solutions for notebooks from Intel and SiS. A Part of the main memory is deducted and used for the VGA frame buffer. As you certainly know, low priced desktop systems are using these chipsets too. From the performance point of view this solution is not optimal. On the other hand there are a lot of advantages of these integrated VGA-solutions, which are predominately the power and size requirements and thus the price.
Many mobile warriors use the notebook for presentations.
It is often necessary that a beamer or a large CRT monitor is connected to the VGA-out. Dual View is supported within mobile VGA chips for quite a while. Typical desktop examples are Matrox 'Dual Head' or one of the new Geforce MX cards with 'Twin View'. Some of those mobile VGA chips also have a TV out option. The notebook designers do not always use this feature though.