The latest Apple MacBook Pro has apparently suffered the first issue only a few days after it has launched. The new MacBook Pro apparently has their SATA interface with the older SATA 1 running at 1.5Gbps. Currently, it is unknown as if it's a software or hardware issue as the latest MacBook Pro should be using the NVIDIA 9400M chipset which should support 3.0Gbps SATA interface.

For most users with conventional hard drives, it should not be an major issue as none of the mechanical hard drives would ever be able to saturate the SATA 1's 150 MB/s transfer rate. Howeer, for those who are running SSD, this can pose some performance lost as Anandtech has shown that customer may experience some lower performance with Sequential read and write if they pair with SSD drives.

Source: Anandtech