Is a 15-inch MacBook Air on the way?

Apple is said to be working on a larger model of its ultralight notebook, with a slightly larger screen. It introduced refreshed models just last week.

Apple's 13.3-inch MacBook Air, currently the largest of Apple's ultrathin notebooks.

After dropping the plastic MacBook in favor of the entry-level, 11.6-inch MacBook Air with last week's round of Mac hardware updates, Apple could be planning to fill out its notebook line numbers with yet another ultralight model, according to a new report.

Macrumors suggested this afternoon that Apple is cooking up a 15-inch "ultra-thin Mac notebook," that will come in slimmer than the company's existing 15-inch MacBook Pro model, presumably with the nixing of the optical drive and perhaps even the hard drive as well.

The blog is not offering up whether it will be a part of Apple's Air or Pro family. Apple's current MacBook Air lineup includes an 11.6-inch and 13.3-inch model, going up to 13.3-, 15-, and 17-inch models on the Pro line. TUAW offers up its own anonymously sourced addition: that Apple is working on an Air-like 17-inch model as well, due out ahead of the holiday shopping season.

Apple completely overhauled its MacBook Air line in October of last year, doubling down with both a 13.3-inch and smaller 11.6 model. At the time, Apple CEO Steve Jobs described the machines as "the future of notebooks."

The company's MacBook Pro line has not seen a massive external overhaul since the company switched to its unibody design in 2008. An iLounge rumor in February suggested that Apple planned to give that line a big face-lift sometime next year.