It would help in certain cases to be able to use regular expressions in the Edit > Find and Replace Text... menu command.
I envision adding a checkbox to enable regular expressions. Also, conditional checkboxes would need to be added to modify the regex with global (g), and multiline (m) flag options, there is already an option for Case Sensitive which could be used for the regex without needing a separate insensitive (i) flag option.
This is a "basic" feature in Bridge Batch Rename and GREP Find/Replace and GREP Styles in InDesign are a must-have for many users. Even though Photoshop isn't a text-heavy app, it would be a great optional feature without having to resort to requiring scripting for such text maipulation.