Microsoft boss Steve Ballmer unveiled the slate PC at CES in January.

"Tens of millions" of tablet computers will be sold in 2010, according to technology analysts at Deloitte.

The keyboard and mouse-free devices are likely to be a top trend among consumers, they anticipate.

Deloitte's prediction fuels rumours that Apple is set to unveil a tablet-style computer at a press event it is hosting on 27 January.

However, the impact of tablet sales on the burgeoning e-reader market could be substantial, the report said.

"For every million net tablets sold there will be a corresponding impact on e-readers," said Jolyon Barker from Deloitte's Technology, Media and Telecommunications department.

The company's report, which forecasts the tech trends for 2010, describes tablets as "the Goldilocks of devices (not too big, not too small)".

It said that previous attempts to launch tablet PCs - notably by Microsoft - had been largely unsuccessful for many reasons.

"The graphics, software, and user interface were underwhelming, not well connected to cellular or WiFi networks, and, most important, they have largely served as work-oriented data-entry devices."

"By contrast, an easy-to-use, consumer-focused device used primarily for media and web browsing is much more likely to be widely accepted by the market."

The report also explored other technologies.

Despite a focus on environmentally-friendly technology at this year's Consumer Electronics Show held in Las Vegas earlier in January, Deloitte predicts that cheaper electricity rates may put a dampener on the demand for alternatives - particularly solar power.

"Solar power technology could struggle in 2010 due to the cost of solar equipment, tools and raw materials, overcapacity and weak economics," said Jim Sloane, Deloitte's lead technology partner.

The firm also predicts that the computer chip industry is going to focus on size and low-cost rather than performance and power.

Deloitte says that this move is driven by portable devices such as netbooks and laptops - especially as the more economical chips require less electric power.