ABC News' Contributor Becky Worley reports:

The Consumer Electronics Show, underway now in Las Vegas, draws 150,000 people each year, eager to see the acres upon acres of brand new gadgets.  The hot trend that's already stealing the show this year is Ultrabooks. Between 30 and 50of these super-thin laptops will be rolled out this week. But, what is an Ultrabook?  Are they as good as the original Ultrabook, the Macbook Air?  Is it worth the extra bucks just to get a lighter laptop?

WHAT IS AN ULTRABOOK? 

An Ultrabook is an extremely thin laptop; no more than .8 inches thick, in some cases as thin as the face of a dime. They run a full version of Windows- this is not just a tablet with a keyboard. And they have super-long battery life: anywhere from 5-9 hours. To stay so thin these laptops have very few ports: usually just headphones and USB 3.0 (for you geeks- I've seen some touted as coming with Thunderbolt ports which are 2X as fast as USB 3.0 and 12X faster than firewire 10Gbps!). These are not as inexpensive as netbooks were a few years ago, but Ultrabooks boast more power. Most new releases I'm seeing start at $899 and go up into the mid $1300-$1500 range.

START UP IN 7 SECONDS

Ultrabooks have no DVD drives.  They have solid state hard drives, which are more like the storage in a USB flash drive than in the older hard drives that spin and have moving parts.

This is important because when you boot up your current computer you're booting up a spinning hard drive: it takes time to get the platter moving and up to speed. But, solid state hard drives in ultra books don't need that time, they start in under 7 seconds.

NEW INTEL CHIPS INSIDE

This category of laptops is coming to prominence now because Intel has just designed the processors that these new systems are based on.  They say that 40 percent of all laptops sold in 2012 will be Windows-based Ultrabooks. Analysts predict as many as 50 new models may be announced at CES but some differ with the Intel projections on sales, predicting more like 10% of laptops sold in 2012 will be Ultrabooks.

NEW AT CES

So which companies announcing what? To name a few:

ACER has the world's thinnest Ultrabook.  At .58 inches, it's thinner than the width of a dime.  Toshiba also says they have the thinnest Ultrabook, but have yet to release exact specs.

ASUS has released a few Ultrabooks in October of 2011 and we expect an update, although possibly only cosmetic, at CES.

TV-maker Vizio is unveiling their own Ultrabook this year.

Dell is rumored to be unveiling a new design.

HP is also rumored to be rolling out an Ultrabook.

MACBOOK AIR

Don't discount the original Ultrabook. Apple unveiled the Macbook Air in 2008, and it was last updated in July of 2011. It costs just $999, but keep in mind it's due for a refresh and may get access to the new processors Intel has created for the PC some time in late spring/early summer of 2012.