By Katie Marsal

Published: 09:55 PM EST

A recently reliable third party claims that Apple plans to launch some NVIDIA-based iMacs at Macworld -- including a possible 28-inch model -- and that Intel's new Core i7 platform may play a greater role in the Mac maker's lineup than expected.

Ryan Shrout of PC Perspective claims to have heard that Apple will have "at least" four iMacs enroute this week that use the NVIDIA MCP79 (GeForce 9400M) chipset that Apple itself has inadvertently confirmed through its own system files referencing unreleased versions of the desktops.

Two of these will reportedly be 20-inch models, with a higher-end version carrying the same GeForce 9600M as for the 15-inch MacBook Pro. Two 24-inch versions are also said scheduled and would use the 9600M in the base model while moving to the much faster 9800M in a top-end version.

Provocatively, however, Shrout also claims to have received word of a new, 28-inch version that would mark a radical break from its smaller counterparts.

Instead of using the 9400M as its foundation, the system would use Intel's X58 chipset and a processor using the Core i7 (previously codenamed Nehalem) architecture. As a result, it would not only include the four cores thought to be present in the upcoming Core 2-based iMac updates but would gain HyperThreading support that at times mimics the behavior of an eight-core system. NVIDIA at most would be used for dedicated graphics in the all-in-one computer.

Other systems are allegedly slated to get updates in the near future as well. Supporting both Apple's leak and others, Shrout believes some form of the MCP79 chipset is bound for the Mac mini but will be underclocked versus that in the MacBook and MacBook Pro, if faster than in the extremely thin MacBook Air.

He also believes Mac Pros will be upgraded to Core i7 architecture early this year; while claiming it will use a similar platform, the processor is more likely to be one of Intel's new Core i7-based Xeons than the consumer-grade parts. Even so, the similarity between the supersized iMac and the Mac Pro tower is described as small enough that the main difference will be the workstation's dedicated graphics, which Shrout hears will use some variant of NVIDIA's GT200 graphics card line.

Some of these systems may not necessarily ship to stores at or shortly after the start of Macworld Expo. The 28-inch iMac and the Mac Pro will supposedly be pushed back to February where the smaller iMacs and the Mac mini are more likely to ship quickly.

Whether or not this latest report is accurate is less than clear. Although he uses a suspected fake mockup of a Mac mini to illustrate one of his points, Shrout's insight was key to confirming NVIDIA-based MacBooks as early as the summer; the technology writer is now thought to have sources close to NVIDIA, which is now effectively Apple's premier partner for mainboards and graphics.

With Phil Schiller's opening keynote just two days away, and AppleInsider's own sources anticipating Mac minis in the near future, these latest claims should be tested soon.