Heimer is a hero that is long overdue for a rework because of the current design philosophy of the characters and the game itself. Many inadvertently counter him without much effort because it's difficult to create heroes with Heimerdinger's turrets in mind and whether they will end up being effective or not.
Riot has changed turrets for the better, how you position them will effect the AI straight down to the animations and so on. However, to balance this all out, Riot has decided to not allow the turrets to be active after Heimer is 1200 range away from them for a period of time. This translates to no more AFK pushing the wave. Overall, the changes look to be positive and hopefully will remove the current "suicide Heimerdinger" gameplay and formulate it into something better.
Full info - Official Forums