The tablet PC market is nearing its three-year anniversary with increased shipments, but mixed success overall, reports In-Stat research firm. Within the next four years the market of such computers is expected to exceed $5 billion per year as a result of price-drops as well as broader software support.

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

The next few years will show some significant growth with the worldwide market of tablet PCs rising from $1.2 billion in 2004 to $5.4 billion in 2009, the high tech market research firm says.

According to In-Stat, vertical markets, such as healthcare, real estate, insurance, and sales force automation, continued to be a driving factor in 2004 tablet PC shipments, whereas Acer, Fujitsu, HP, Motion Computing and Toshiba were among the leaders in 2004 Tablet PC shipments. This means that other mobile computer manufacturers have to catch up with tablet PC models. For instance, Lenovo recently unveiled the first ever IBM-branded tablet PC.

The research firm believes that availability of an integrated next-generation tablet PC operating system in Microsoft’s Windows Vista operating system would have a significant impact on Tablet PC sales. Furthermore, Microsoft’s recently announced Ultra Mobile 2007 portable PC form-factor could have a significant impact of future tablet PC shipments.

The report, “Tablet PC 2005: Increasing Shipments Amid a Cloudy Future”, contains worldwide annual unit shipment and revenue forecasts for tablet PCs through 2009, and an annual regional breakdown of Tablet PC shipments through 2009. Also included are 2004 tablet PC shipments and revenues by vendor, as well as 2004 vendor shipments by region. Extensive analysis of Tablet PCs in both horizontal and vertical markets is included, as well as the potential of Tablet PCs in the consumer segment.