Samsung is raising the bar when it comes to mobile storage, with their announcement of a 200GB 7200RPM 2.5" hard drive. Their "SpinPoint MP1" series will have other capacities as well, and come with up to 16MB of cache. Aside from that, it has everything you'd expect from a modern laptop HDD, such as enhanced SATA features like NCQ and noise reduction. Interesting enough, Samsung is not pitching this drive at laptops. Instead, they are aiming it at workstations and servers where space is a premium, such as with blades. Pricing hasn't been made available just yet.
Mobile performance is being pushed to ever-greater heights. One of the biggest bottlenecks, the hard drive, has seen many improvements the past few years, including the very recent first introductions of solid state disks. It'll be a while before those are affordable, though, and in the meantime, many manufacturers are continuing to push both the limits of space and speed in tiny platforms.