DYI folks with an interest in home automation are a natural market. Of course, the features of a central controller will be important. Also, with drip irrigation in mind, the three hour limit on runtime is a bit low for some installations. Not many, for sure. As for weather information controlling irrigation cycles, look at a Toro Intellisense controller for one variation on the theme.
The major companies like Toro, Rainbird, and Hunter, already have computer controls, for golf courses and other large systems. Wireless controls might be worth pursuing, but they have to work in the real world. Hunter was probably first with residential controllers capable of working with a transmitter/receiver kit to allow remote control of a sprinkler system, but the very-low-power controller circuitry makes long cable runs from controller to transmitter plug a problem, due to stray emf. The transmitter also has problems around masonry. Four hundred foot line-of-sight range becomes less than ten with enough concrete in the way. There are FCC rules and regulations that affect the capabilities of their wireless operations, said Hunter, when I asked about them.