Simply purchasing Fallout 4 on Steam gets you access to the Mister Handy-led "limited time offer" Fallout 4 announcer pack. It'll be made available by "mid-November", shortly after Fallout 4's November 10 release date. Anyone who buys Fallout 4 before the end of November will get the announcer pack. One assumes it'll also be sold separately.
As of yet, we have nothing to hear from Mister Handy in Dota, so let me share with you this video of him/it reciting Sara Teasdale's 1920 poem There Will Come Soft Rains - my favourite of his many Fallout appearances:
Since it's the weekend, I'm going to take the liberty of sharing the verse in old fashioned text-form, should you wish to recount it alongside our automaton companion (1940's English public broadcaster dialect optional):
There will come soft rains and the smell of the ground,
And swallows circling with their shimmering sound;
And frogs in the pools singing at night,
And wild plum trees in tremulous white,
Robins will wear their feathery fire
Whistling their whims on a low fence-wire;
And not one will know of the war, not one
Will care at last when it is done.
Not one would mind, neither bird nor tree
If mankind perished utterly;
And Spring herself, when she woke at dawn,
Would scarcely know that we were gone.
Well said, Handy. And well said reader, if you joined in too.