It's up for NA for sure, not sure about EU, but it's being bombarded. You'll get about 35 errors to every one time you actually get in. I redeemed my DiRT 3 code and pre-order code (and picked up a couple motorstorm avatars) before playing online, but now it seems it's even worse and I can't get any codes put in. Oh well, wait until the morning.
But, on the upside, DiRT 3 online was pretty fun 👍