Update: It appears the issue is fixed as quick as it came to be! Xbox Support has said that the store should be functioning and purchased games and apps should load. Hurray!
Original Story: It's been a while, but it seems a pretty substantial outage has hit Xbox Live. Owners are currently unable to load any digital games or apps, as well as purchase any form of content on the store.
As of right now, it only appears to be hitting European users, but that's not to say other territories aren't affected. Xbox Support has acknowledged the issue and is working on a fix as you read this.
Unfortunately, we don't have any ETA on when this problem may be solved. From testing, we've been able to load up physical games just fine, so you may have to play disc based titles for a while. Parties, messages, and other elements of Xbox Live all appear to be fine too. We'll keep you posted when we have an update.
Been affected by the issue? Let us know in the comments below.