Apple has stopped selling the MacBook Pro until Thursday as its online store states that MacBook Pro's will ship in 3-5 business days, giving credence to reports which say MacBook Pro lineup is due for a refresh.

Reports of a possible upgrade coming to MacBook Pro lineup have been doing rounds since December 2010, when DigiTimes reported that certain upstream component makers had confirmed that Apple planned to launch about four upgraded MacBook Pros and an iMac with new panel size with a new price point. Foxconn Electronics and Quanta Computer were expected to receive the orders for these devices

In January MacRumors reported that supplies of MacBook Pro models of 15-inch and 17-inch models were running low. It reported that Amazon was quoting a shipment timeframe of 1-2 months for the Core i5 model.

Also AppleInsider reported last week that Best Buy listed five new Stock Keeping Units (SKU) for MacBook Pro at price points ranging from $1,199 to $2,499. The price points revealed that the notebooks will be priced at $1,199, $1,499, $1,799, $2,199 and $2,499, giving more weight to the assumption that the upgraded MacBook Pro's will arrive in 5 different configurations. PCWorld quoting an Italian site iSpazio, reported that the new models will sport five models with sizes 13, 15 and 17-inch screens.

The most anticipated update is that the MacBook Pro lineup will be powered by new Intel Sandy Bridge processors and will sport solid-state drives. PCMagazine reported that MacBook Pro lineup will receive the new Sandy Bridge MacBook Pro update by March 1. However, reports of delayed shipment could mean that the new CPU's could arrive by Feb. 24.

The MacBook Pro lineup currently includes variants which come in 13-inch, 15-inch and 17-inch with each variant offering different configuration. Like the 13-inch MacBook Pro come in two models with one sporting a 2.4GHz processor and the other, a 2.66GHz Intel Core 2 Duo chip. The 2.4GHz model offers 4GB RAM with 250GB hard drive while the other offers 4GB RAM with a 32GB hard drive, and both offer 10 hours of battery life.