The discount is available in Ireland & the UK and the USA and brings the price down to £89/$89.
I'm not sure if it's being extended to Canada, one of the two new regions where AncestryDNA has recently landed (see blogpost) but it might be (see UPDATE below), so Canadian researchers should try clicking on the image to the right; Ancestry's geographic widget should take them to the relevant local page if the offer is available there.
It isn't available in Australia, the other new AncestryDNA region. Simple reason: Australia doesn't celebrate Father's Day until September.
Note that the offer does not include shipping costs or applicable taxes, which can bump the price significantly.
UPDATE 17 June: Ancestry has confirmed to me that the discount is not available in Canada.