Apple has begun offering 8 GB RAM upgrade kits for the 2.93 GHz and 2.66 GHz models of the latest unibody 15" MacBook Pro, despite the published technical specifications claiming support for a maximum of 4 GB in these higher-end models. Apple is not currently offering the 8 GB kit for the entry-level 2.4 GHz 15" MacBook Pro, which also claims support for a maximum of 4 GB of RAM.
While Apple computers frequently support additional RAM beyond the published maximums, Apple typically limits its recommended RAM offerings to those maximums. This requires customers wishing to upgrade to higher RAM kits to either purchase Apple RAM kits intended for other models using the same RAM but supporting the higher maximum or turn to third-party suppliers who frequently offer such kits advertised for models that unofficially support the higher RAM configuration.
Apple's 8 GB RAM kit retails for $1200, significantly higher than similar offerings from many third-party RAM vendors.