No Zing for the Zune

Several SanDisk (SNDK Quote) and Creative (CREAF Quote) players also are selling faster than the Zune on Amazon.

"This is one online retailer's perspective, but I think it's reflective of the marketplace as a whole," Gartner's McGuire says. "iPods are clearly dominating."

"That's not terribly surprising. Given Apple's dominant market position, it was unlikely that Microsoft was going to come in and make a significant dent," Gartenberg says.

Yet don't expect Microsoft to throw up its hands if Zunes sell poorly over the holidays, Gartenberg says.

The iPod has become a gateway into the digital home for Apple, Gartenberg says, which threatens to encroach on Microsoft's efforts there. Early next year, Apple is planning to launch a device, code-named iTV, that will allow people to stream movies, music and photos from their computers to their home-entertainment systems. In addition, it's been growing its computer sales at a rapid clip and has made moves to reach more mainstream customers.

Meanwhile, "Over time, (Microsoft) needs to look for new sources of revenue that aren't based on the PC," says Chris Crotty, a senior analyst with iSuppli. "They need to find ways to tap into the consumer electronics market."

While Zune is one of those steps into the nascent digital music market, it seems the Redmond behemoth still has a long way to go to impress music fans and critics.

"If any feature on the Zune becomes successful, it would be easy for Apple to replicate," Crotty says. "But it's harder for Microsoft to replicate Apple's success in the market."

Apple shares recently tacked on $1.52 to $91.06, while Microsoft dipped by 14 cents to $29.34.