The tablet category has significantly expanded its role in the lucrative mobile PC market, with shipments hitting 72.7 million units and accounting for 25.5% of mobile PC shipments in 2011.
"In the short term, tablet PCs will be the growth accelerant in the overall mobile PC market, as macroeconomic factors and hard drive motor supply issues impact the market for notebook PCs," explained NPD DisplaySearch analyst Richard Shim.
"In the longer term, notebook PC shipments will bounce back as ASPs continue to decline, Windows 8 launches, and new form factors, such as Ultrabooks, continue to emerge."
According to Shim, notebook PC shipments are projected to reach 432 million units by 2017, while tablet PC shipments are expected to reach 383.3 million units.
"Ultrabooks are an emerging form factor that is expected to contribute to demand in later years of the forecast. Demand for ultrabooks will be driven by consumer interest in sleek design and convenience like instant-on and long battery life," said Shim.
"[However], for the next two years, the premium price points of Ultrabooks will temper demand, and there may be some supply limitations in production of displays thin enough for Ultrabooks."
Shim also noted that future tablet PC shipments will be driven by increasingly powerful multi-core processors, mature operating systems, growing application libraries, and higher resolution panels.
"[Similarly], mobile PC shipments will be up in late 2012 and 2013 with the introduction of Microsoft's Windows 8 operating system and new mobile processors from Intel," he added.