Though P.C fans are loath to admit it, non-Apple OEMs have been forced to play catch-up to Apple in many ways – mostly in the market of small form factor laptops and tablets. While Apple invented neither of form factors, they certainly dominate in these markets. The Macbook Air, for instance, has sold incredibly well since it was first introduced in 2008.

To play catch-up to a noticeable consumer preference for computing in thin-and-light style, P.C OEMs introduced the Ultrabook and, for AMD, the Sleekbook.

While these offerings seem promising, a new report from Digitimes Research projects that non-Apple ultrathin vendors are unlikely to surpass Apple in 2012.

Joanne Chien, who authored the report, argues that Apple’s steady 50% hold on the ultrathin market combined with the low growth rate in P.C ultrathin vendors, as well as the 15% drop and 2% drop from Toshiba and H.P, respectively, are a guarantor of Apple’s continued rule in this particular market.

Apple’s ultra-thin MacBook series products (MacBook Air) already account for 50% of global notebook shipments that feature an ultra-thin design in the second quarter and Apple’s MacBook Air shipments in the fourth quarter are still expected to surpass the combined shipments of the non-Apple notebook brand vendors’ ultrabook and ultra-like notebook products, Chien noted

Apple’s ultrathin competitors also have another hurdle to leap in their quest to be king of the market: a shortage of unibody aluminum chassis parts.

Digitimes’ publication arm is reporting that suppliers of the in-vogue chassis can’t keep up to demand, noting that two of the major suppliers – Catcher Technology and Foxconn Technology – won’t be able to fulfill demand through the end of 2012.

Wired was able to catch up with an analyst from IHS who painted a pretty bleak picture of the situation.

“Apple has really consumed a considerable portion of the currently available [manufacturing] capacity because they use the casings exclusively in their notebooks,” IHS principal analyst Tom Dinges told Wired. “Not to mention, Apple’s notebook volumes have grown considerably faster than the overall market the past few years, which adds even more strain to the available capacity for these casings.

Digitimes says that to get around this shortage, some OEMs may turn to fiberglass for fabrication.

This however presents a challenge for manufactures as some consumers may see fiberglass as a cheap flimsy analogue for metal.

With Windows 8 expected for the fall, will OEMs be able to supply enough P.C ultrathins to market?