What do you mean? What has the color picker changed to?
Did you open the color book picker, or the 32 bit/channel / HDR color picker?
Did you accidentally select the OS color picker in Photoshop's preferences?
Here is the link to the information that was helpful to me: http://planetphotoshop.com/color-picker-versatility.html
I had deselected the H button (on the right hand box with descending order of H S B I had instead selected the S button and so the format
that came up consistently was for Saturation instead of Hue.