What are the implications for a company's customers if its main patent has been assigned to a competitor after litigation?

It would appear that the patent rights now reside with the competitor, and that current sales by the original company would comprise infringement of the patent rights of the competitor - unless, of course, there was some agreement to the contrary as a result of the litigation - maybe there was a license granted back to the original company, maybe the agreement stated that the original company could exhaust all currently produced products but could not engage in the new production of products. I do not believe that the company customers would be held liable for any infringement - all infringement, if in fact the original company was immediately prohibited from selling any of the patented products, would be the liability of the original company.

I have to respectfully disagree with Michael - while a purchaser of a patented product would obviously be "using" the product, and therefore technically infringing the patent, I do not believe that liability, if any, would be adjudged against such user - the primary infringement, and damages, would be against the company making and selling the patented products.