Canon has a announced a new midrange flash to replace 430 EX II. The new Canon Speedlite 430EX III-RT adds support for radio-based wireless control and is faster, smaller, and lighter than its predecessor. Using the traditional optical/infrared system the 430 EX III-RT, like it's predecessors, can only work as a slave unit, but when using radio wireless flash control, the new flash can work both as a master or slave unit. The guide number remains at 43 (43m at ISO 100).
The 430EX III-RT will be available in mid-September for an expected retail price of $299 in US, £249 in UK or €349 in EU (Linked prices may vary).