In big IT companys, they prefer to have their own frameworks which will definitely wrap best practice(patterns) or common service to benefit from reuse/flexibility/stability/time to market etc. So, in this case, most of "developers" do not need to know patterns and how to use them, there only need few experts in architecture/design/patterns.
Like other frameworks(Spring/Struts/Hibernate, these mainly for one function module), "developers" only need to know how to configure the whole system working with the XMLs.
These days, reading <Head Frist Design Patterns>, feeling that I must know more about the essence.
although We need to use FrameWork sometime, I think DP is important too. I have read a book named <<Refactoring to Patterns>>.It tells me a new sight about using Pattern. Pattern is not only can be use in design,It can make your code more flexible and eliminate duplicate through refactoring. and I think these is the core use that Gamma think DP can do