If you take the same height, then bring the width to 16:9 ratio (plus the border), the iPad would be about 12.25 inches wide, instead of the current 9.5 inches wide. Nearly three inches wider would make it a bit more cumbersome.
16:9 is only for movies/TV. Most of what people do with the iPad is web surfing. Like others have said, there is no reason to make a sacrifice for one application, when a 4:3 screen is much better for nearly all other applications and for aesthetics.
The same goes for a computer screen... bit the main reason for going with widescreen notebook is that it actually makes more sense due to the form factor. Now, if keyboards were more square than rectangle, it would make sense for the screen to match that shape. With a notebook, you can't really make the screen wider than the keyboard. The only variable is height. A widescreen notebook computer is actually more compact, because the screen is just shorter than it would be if it were 4:3.
16:9 is only for movies/TV. Most of what people do with the iPad is web surfing. Like others have said, there is no reason to make a sacrifice for one application, when a 4:3 screen is much better for nearly all other applications and for aesthetics.
The same goes for a computer screen... bit the main reason for going with widescreen notebook is that it actually makes more sense due to the form factor. Now, if keyboards were more square than rectangle, it would make sense for the screen to match that shape. With a notebook, you can't really make the screen wider than the keyboard. The only variable is height. A widescreen notebook computer is actually more compact, because the screen is just shorter than it would be if it were 4:3.