Hodgdon
IMR has released a new line of pistol powders
A new Enduron powder is being released called IMR 8133, which is the slowest yet in the series.
Winchester WinClean 244 is a ball powder developed for medium handgun loads. It is ideally suited to 38 Special, 45 Auto, and 9mm standard loads. It's burn rate is between 231 and 296.
Alliant
While not exactly new, Alliant is releasing reformulated versions of Red Dot and Green Dot that are cleaner burning.
Vihtavuori
Vihtavuori is releasing a new powder in their 500 series.