sry what i really meant to say was laptops merged with a phone like that, with internet that comes for free with the cellphone bill and stuff like that
I see the standard monitor size hitting 22" easily. Computer towers will get smaller, sleeker and offer more "style" for the buyer. I think companies will begin to focus more on efficiency and ability of their components rather than raw power and size. Just like how multi-core processors replaced single-core processors, this will continue to be the trend for many other parts to come. You won't need to have three video cards SLI'd to have the best graphics for games.
I also see huge, affordable hard drives popping up in the near future. 2, 4, 5 TB storage for affordable prices.
Oh, and something nobody touched on yet... I have a feeling that touchscreen monitors will be leading the industry in 5-10 years. Bigtime. Moving icons around with your fingers, resizing windows/photos with pinching (like on our iPhones) etc.