What will this do for the people who dont have private investigator licenses?

If you do work without it then you are committing a felony.

The actual bill is located here.

It's not the easiest thing to read (legalese plus poor formatting), so I'm slowly making my way through it. 

SECTION 16.  Section 1702.324, Occupations Code, as amended
     by Chapters 518, 728, 1102, and 1155, Acts of the 79th Legislature,
     Regular Session, 2005, is amended by reenacting and amending
     Subsection (b) and adding Subsection (c) to read as follows:
            (b)  This chapter does not apply to:
                  (1)  a manufacturer or a manufacturer's authorized
     distributor while selling [who sells] equipment intended for resale
     [and does not perform any other service that requires a license
     under this chapter];
                  ...
                     ...
                  (6)  a licensed engineer practicing engineering or
     directly supervising engineering practice under Chapter 1001,
     including forensic analysis, burglar alarm system engineering, and
     necessary data collection;