Lenovo is expected to announce a new model tomorrow in its highly regarded ThinkPad X series of ultraportable laptops that offers a USB 3.0 port, a uniquely sized 12.5-inch screen, and long battery life, as CNET reported earlier today.

The X220 appears to be a variation on the previously announced Lenovo IdeaPad U260 theme. That IdeaPad, like the ThinkPad X220, is 3 pounds and offers a 1366x768 resolution 12.5-inch screen.

But there are some significant differences, the most salient being the ThinkPad's use of dual-core Core i7, i5, and i3 Sandy Bridge processors and a USB 3.0 port option. USB 3.0 delivers data transfer speeds "up to 10 times that of USB 2.0," according to Lenovo.

Other differences include better battery life, the option for Intel 80GB and 160GB solid-state drives, and configurations with built-in 3G.

The ThinkPad X220 has a uniquely sized 12.5-inch screen, packs Sandy Bridge processors, and a USB 3.0 port in one model.

Let's take a closer look at the Sandy Bridge processors, as they likely presage future versions of the MacBook Air and other ultraportables from top-tier vendors. The top-line X220 comes with the 2.7GHz Intel Core i7 2620M processor and a USB 3.0 port. Other models use Sandy Bridge Core i5 and i3 chips, including the i5-2540M (2.5GHz), the i5-2410M (2.3GHz), and i3-2310M (2.1GHz).

Lenovo's claims for battery life are stunning. With a standard 9-cell battery, the X220 boasts up to 15 hours battery life. This jumps to up to 24 hours by adding a ThinkPad Battery 19+ external battery, according to Lenovo documentation.

An "Instant Resume" function is also standard. This maintains wireless connections during sleep mode for up to 99 minutes, "eliminating the need to login and reconnect between meetings," said Lenovo.

Other features include an SD card slot, an Express Card slot, Display Port connector, and Intel integrated HD graphics.

The ThinkPad X220 will be available starting in April. Pricing starts at $899.