EA sent me an email telling me that The Sims 2 IKEA Home Accessories will be available soon.
So I had a look at the website, and it told me that if I pre-ordered with participating online retailers, I'd get some bonus items.
The problem being that the bonus items depended on who I pre-ordered with! Hm, decisions, decisions.
In the end I went with weltbild.de, partly because they had an office chair very similar to the one I have at home, and partly because they promised free shipping if you have the items sent to one of their shops.
In the end, it turned out that the game is not eligible for this (though it didn't tell me why not), but I ended up buying with them anyway. And with Amazon.de, the other main possibility (besides the EA shop itself), I would have had to pay shipping, too, since the order would have been under €20. Ah well.