Apple's tease of a "product transition" in the works sparked debate among pundits Tuesday about what the Mac and iPod maker may be planning.

In a conference call Monday, CFO Peter Oppenheimer told financial analysts that product development contributed to a drop in gross margin in the fiscal second quarter to 34.8%. Moreover, the "product transition" would help push the margin, also known as gross profits, down further in the current quarter to 31.5%, and keep it around 30% in fiscal 2009.

Costs associated with new products are often high in the beginning. Expenses, however, drop over time because manufacturing gets cheaper as more product is produced and component prices from suppliers are lowered.

Oppenheimer declined to provide even a hint of what Apple is working on, but promised it would be "state of the art" and unmatched by rivals. Those comments sparked a firestorm of speculation among Apple watchers on the Web.

AppleInsider pointed out that several product categories are due for a refresh, such as the MacBook, Mac Mini, and iPod. The news site also mentioned that observers believe that Apple is developing a multitouch tablet.

TheStreet.com's Gary Krakow was one believer in a tablet computer, saying it would likely be based on the popular iPhone touch screen. MacRumors said the device could be a 12-inch or 13-inch Mac tablet that would ship in September or October.

Gene Munster, analyst for Piper Jaffray, suggested in a note to clients that an overhaul of the MacBook and MacBook Pro was overdue, and introducing upgrades in time for the back-to-school season made sense, particularly if the starting price was lowered to $999, Fortune magazine reported in its Apple blog.

Ezra Gottheil, analyst for Technology Business Research, said in a note that Apple is likely to refresh its notebooks with the latest Intel Centrino 2 processors, which would boost performance and increase battery life.

In addition, Gottheil expects a redesign of the MacBook, the addition of TV tuners to the notebooks, and the introduction of quad-core processors to the MacBook Pro. "iMac desktop PCs are not likely to get a dramatic overhaul, but Apple will probably beef them up," Gottheil said.

While Apple fans won't know for sure what the new products are until they're released, the latest round of speculation does demonstrate how Apple can generate marketing buzz by what it doesn't say.