It's been 311 days since Apple last introduced an upgrade to its MacBook Pro series of computers. Coupled with both supply shortages and delayed shipments of online orders, the evidence for an imminent update to the MacBook Pro seems irrefutable. With Steve Jobs turning 56 Thursday, speculation points to tomorrow as the day new models would be available in stores. In anticipation of the announcement, let's examine some of the most likely improvements Apple will take with the MacBook hardware.