.45 ACP is not being fazed out. However, 9mm has had a new resurgence due to manufactures creating 9mm ammo with a big "punch", popularity of concealed carry and the micro or pocket 9's. Also, a number of shooters have come to realize that, after shooting 40S&W, they simply perform better with 9mm. More power isn't always better.
If CC laws become far more restrictive, people will gravitate toward larger guns and therefore .45 and 40S&W.