The following post was put together by Stuart Hayes of the Dell Linux Engineering team.
Hard drives have traditionally (pretty much always) used 512 byte "sectors" (or blocks). When a drive is accessed, it is given an address which points to a sector (or, more recently, it is called a "logical block address").
As physical drive geometry shrinks, it has become increasingly difficult for drive manufacturers to support 512 byte sectors, and they are now switching to 4096 byte (4KB) sector drives. The first drives will be called "advanced format" drives, which still CLAIM to use 512 byte sectors, and are still addressed that way, but really use 4KB sectors internally... this means that existing operating systems can use them without change. Later, "true" or "native" 4KB sector drives will become available. There are changes required to support true 4KB sector drives in the operating system and drives, as well as the firmware (BIOS).
While our currently shipping firmware and Linux distributions don't yet support this, I recently was able to install Linux onto a system with a true 4KB sector drive. It successfully booted with that drive, demonstrating that Linux (and our firmware) is ready for 4KB drives.