The Tablet PC market is nearing its three-year anniversary with increased shipments, but mixed success overall, reports In-Stat. Referring to PCs that run Microsoft’s Windows XP Tablet PC Edition operating system, Tablet PC shipments have yet to reach the top shipments that some backers predicted upon launch. The next few years will show some significant growth, however, with the worldwide market rising from US$1.2 billion in 2004 to US$5.4 billion in 2009, the high tech market research firm says.

“Broad horizontal corporate markets should start to make an impact on the market in 2005, as average selling prices fall well below $2,000,” says Brian O’Rourke, In-Stat analyst. “A combination of greater Tablet PC software availability and larger form factors that directly address the corporate market should help Tablet PC sales.”

A recent report by In-Stat found the following that vertical markets, such as healthcare, real estate, insurance, and sales force automation, continued to be a driving factor in 2004 Tablet PC shipments.

Acer, Fujitsu, HP, Motion Computing and Toshiba were among the leaders in 2004 Tablet PC shipments.

Also according to this report, availability of an integrated next-generation Tablet PC operating system in Microsoft’s Longhorn operating system would have a significant impact on Tablet PC sales.