Preview at WWDC likely in June, followed by September launch.
Apple to Give Employees $500 Off Macs and $250 Off iPads
The new discount program starts in June 2012, and can only be used once every 3 years. Employees also need to have been working at Apple for at least 90 days. The discount is reportedly for both corporate and retail employees. The discount is said to exclude the Mac mini.
Apple employees presently are allowed a one-a-year 25% discount on Apple systems. One report even claims that this discount will remain in place alongside the new discounts.
In 2007, shortly after the original iPhone's launch, Apple had announced a similar perk for employees. At that time, Steve Jobs announced that all full time and part time Apple employees would receive an 8GB iPhone.