I know what you were thinking--or at least I know you know what I was thinking--when you saw that new Ikea PS series Laptop Workstation on minor details last week: sweet, but could you make a wall-mounted changing table out of it?
We have several of the PS series lockers tucked around the house for storage; they're clean and sturdy and weirdly cheap, and we love them. So when the kid and I had our mom's-away meatball dinner date Saturday night, I went to scout the Workstation out. The verdict: the measurements are doable, but I'd like to reinforce that dropdown shelf before I commit any kid bigger than a newborn to it.
Pros: the work surface measures 15Dx24W inches, which happens to be almost exactly the dimensions of the basic Ikea changing pad, the inflatable, 3-sided Gullunge. There are interior shelves aplenty, at least 7" deep, [The whole unit is 7 7/8" deep.] which could hold all the changing gear you need. The pop-open storage space underneath is handy when you don't want to open the whole thing.
Con: the work surface is not weight-rated. I'm sure a 20-lb baby'd be fine, but how do you test? If you epoxied a steel L-bracket on the backs of the two flanges which support the whole top, it'd be more reassuring. You want to keep a changing pad from slipping around, yet you can't attach it permanently, because the shelves get in the way when you close it. [Possible solution: some no-skid tape or backing on the bottom of the pad. Then stash the pad using the handy, included elastic screen holder. The corners are pointy and metal, though you won't need to worry about it until the kid's walking and reaching work surface height.
If you're going to put a kid on there, you'll want to bolt that thing to studs, definitely more than drywall. If you're feeling adventurous, you've got some nice metal flashing, and your walls are deep enough, you might even consider embedding it flush. Whatever you do, please send photos.