According to Engadget Hitachi has announced two new 500GB 2.5 inch hard drives, the 5K500 and the E5K500.
Even if it is a great success but there's one downside to this.This jump in storage didn't come from advancements in storage technology -- it came from Hitachi cramming another platter onto the stack. More platters equal more thickness, and the 5K500 and E5K500 are 3mm thicker than your industry-standard 9.5mm thick 2.5-inch drive. In other words, Hitachi copped out in the race to 500GB and created a non-standard sized drive that more than likely won't fit in your laptop or external enclosure.
They will start at a price tag of $400 (the E5K500 will likely cost a bit more, it's the enterprise drive with bulk data encryption and is rated for 24/7 access) and will be available in February.