By Katie Marsal

Published: 06:40 PM EST

Apple's upcoming quarterly results report will impress investors with extremely strong Mac shipments as the star of the show, predict research notes from American Technology Research and RBC.

Analyst Mike Abramsky of RBC is particularly aggressive in estimating Apple's success. He argues that the back-to-school season and new iMacs will have given Apple a "powerhouse momentum" in the market, triggering shipments of slightly more than 2.2 million Macs in the summer quarter. The amount would equate to 55 percent more systems sold year-over-year and would represent an all-time high for the company.

Meanwhile, senior analyst Shaw Wu of American Technology Research is more conservative, but still describes Apple as drawing "strength" from the 2.0 million Macs his firm estimated would ship from the Cupertino electronics giant. He shares RBC's general consensus on back-to-school sales but notes that the strong sales show general popularity even at the high end of the Mac product range, rather than a rush to buy computers for dorm rooms.

"Students don't usually load up on $1800-2k Macs," Wu says.

Both are also optimistic about Apple's iPhone shipments. The cellphone's sales have only picked up since the price drop and are said to account for sales above expectations from either investment group, with Wu's firm anticipating 900,000 iPhones sold during the latest quarter and Abramsky calling for 1 million. The launch of the iPod touch has had very little if any effect on iPhone sales, the two researchers say.

The rapid growth in Apple's product lineup has also provided a last-minute boost to Apple's lineup, but has generated unusually balanced sales across the lines, according to the two experts. As with past models, the new iPod nano is described as the clear sales leader; it has been responsible for as much as 50 percent of all iPod sales in the last few weeks of September, Abramsky estimates. Even so, sales of the significantly more costly iPod touch are also particularly strong and should help Apple sell either 9.5 million iPods (according to Wu) or 11 million (Abramsky) during the quarter.

Virtually the only dfference in core beliefs between the researchers is their approach to the conventionally-styled iPod classic, which Wu says is "doing well" while Abramsky claims it has been "waning" as customers are drawn to the iPhone and iPod touch.

RBC's analyst adds that the expected results, however positive, are likely to be muted relative to holiday growth. Many of Apple's most anticipated products -- including Mac OS X Leopard, European iPhones, and a possible subnotebook -- are only predicted to launch during the holiday quarter or shortly afterwards. Apple may have nonetheless boosted some of its sales in Europe simply through the sheer media frenzy surrounding the iPhone.

"Just like iPod growth/penetration aided North American Mac growth, in phone-centric Europe and [internationally], we see the launch and publicity of the iPhone aiding Mac awareness and assisting subsequent market share gains," Abramsky says.