Apple is allegedly preparing a refresh of MacBook Pro in the late 2011, and possibly before the end of the month, according to sources.

The new models of Apple's Macbook Pro will come with speedier Intel processors, but would not have major updates otherwise, according to AppleInsider's people with proven insight into Apple's future product plans.

The refreshed line could be introduced as early as before September ends, following the end of Apple's Back-to-School promotion on Sept. 20. 

Intel has just announced its new Sandy Bridge lineup of processors last week, adding new Core i7 chips. This would lead Apple to replace the current 2.0GHz, 2.2GHz, and 2.3HGz processors featured in the 15- and 17-inch MacBook Pros with the new 2.4GHz, 2.5GHz, and 2.7GHz quad-core i7 processors.

While Apple is not reducing the inventories of existing models, the slight spec-bump is to have MacBook Pros, the company's top-selling notebook family, remain competitive in the market until Ivy Bridge platform is released somewhere in the first half of 2012.

On Wednesday, Apple issued EFI firmware update for Macbook Air system to address issues with Lion Internet Recovery and compatibility for the upcoming Thunderbolt displays that Apple is developing. Following this update, Apple released updates for Mac Mini and MacBook Pro to offer stability enhancement for Lion Internet Recovery, Apple Thunderbolt Display compatibility and Thunderbolt Target Disk Mode.