The iPad will be the biggest star in the sky, but not the only one, Forrester predicts.

Forrester Research has more than doubled its long-term sales forecast for tablets to reflect consumer demand.

About 10.3 million tablets were sold in the U.S. last year, the market researcherestimates. It expects sales to more than double this year to 24.1 million units. From there, sales growth will gradually start to plateau with 35.1 million units, 39.8 million units, and 42.3 million units sold in 2012, 2013, and 2014, respectively. Tablet makers will sell 44 million units in 2015, the researcher predicts.

As recently as June, Forrester was predicting tablet sales to reach 20.4 million units in 2015.

As tablet sales increase, the number of people using those devices is obviously expected to grow as well. By the end of this year, Forrester expects 26 million U.S. consumers to use a tablet. That figure is expected to increase to 50.7 million consumers in 2012 and 67.7 million folks in 2013. By 2015, Forrester predicts, 82.1 million people will be using tablets in the United States alone.

Forrester said tablets have become "lifestyle devices," making the rate at which consumers opt for a new tablet closer to that of a smartphone than of a PC. In fact, the company believes that a "significant number of first-generation iPad buyers will buy iPad 2 when it comes out this year." The old Apple iPad units, it says, will be given to "kids in the back of the car."

Given the popularity of the iPad, Forrester believes that competitors, such as Research In Motion's BlackBerry PlayBook and Android-based tablets, "will take a backseat to Apple." However, Forrester also noted that due to the size of the tablet market, "there's room for more than one player."

That's good news for the many vendors expected to show off their first tablets at CES this week. One such company, Vizio, jumped the gun and announced its Via tablet yesterday. That device boasts a 1GHz processor and 8-inch touch screen. It comes with wireless-N connectivity and Bluetooth, along with HDMI output.

If you want to find all the tablet announcements expected in Las Vegas this week, be sure to keep checking CNET's CES blog.