Since you mention the current hard drive, I'm assuming you are referring to the internal hard drive connector which is SATA. Other than the mounting sled, the connectors are standardized so if considering replacing the HDD with an SSD or something like that there should be no problems (outside of putting the new OS onto the SSD - that's just a time consuming pain). Your current HDD is 9.5mm thick while most SSD's are 7mm thick but the sled will make the swap possible even with a 7mm thick drive
If I'm missing something, please clarify