While we’re beginning to see more of the thin and light Ultrabook computers surface, they’re not taking the spot of the ultra-cheap netbook computers quickly, and we think we know why.

According to a new report, the problem comes down to the cost of components used just not being cheap enough yet.

For one, the hard drive technology can be expensive, with solid state drives often used. These drives – with sizes around 64, 128, and 256GB – are lighter, faster, and require less power than conventional hard drives.

The shift to metal bodies is also making a dent, as companies scramble to come up with a lightweight metal that’s both flexible and strong. Apple has been using aluminium for years, and we’ve certainly seen our fair share of magnesium alloy on Lenovo and Toshiba, but now it seems that everyone wants a piece of the action.

Of course, some of the Ultrabooks we’re seeing don’t actually use solid state drives or metal bodies, with regular mechanical hard drives seen in some of the models as well as plastic casing.

But the premium components that make a laptop thin and light appear to be pushing back a big price drop, and from what we hear, that won’t change until 2013.