Marcus Overhagen announced that his AHCI SATA driver is now ready for testing. If you have an AHCI compliant chipset, and a SATA hard drive attached, you may want to give his driver a try.
Most current motherboards are AHCI compliant - it is the defacto SATA device driver standard. This driver allows you to run Haiku on modern hardware natively, without using a PATA emulation that may be provided by your BIOS.