Update: Blizzard have officially revealed D.Va's introduction to SC2 - as both an icon and an announcer pack.
As predicted, Overwatch's D.Va will make her debut in StarCraft 2 as a voice-over pack. BlizzCon will reward a player icon to those who attend the show or watch at home on the Virtual Ticket, while the announcer will be available for purchase by all at a later date.
The BlizzCon schedule and associated rumours were also revealed last week.
This info debuted in a blog post on Battle.net along with various voice lines that D.Va's omnipresent voice will spout. They're typically in-character with the sort of internet leet-speak nobody's actually used since 2007 or spoken out-loud ever. Hopefully that's part of the charm for you.