It’s a small thing, but it’s very thoughtful of them. Ikea (they probably got the idea from someone else) added drainage slots to the bases of their coffee cups so that they dry better.
This is particularly good news for users of dishwashers: there are few things more annoying than sprinkling brackish dishwasher juice from the base of a mug over a load of otherwise clean and dry dishes as you empty the dishwasher.
Ten magic points to Ikea for innovating on something that didn’t look like it needed it but actually did. This is how the world gets better.