Reports suggest that Xbox Live users are experiencing slow download speeds in Europe and other regions. However, Microsoft is looking into the situations, but it also wants you to try out steps mentioned on their Troubleshoot Page, before you start complaining.
Microsoft rep responded to a fan:
Hey, guys! We’re currently tracking this, but we need a few things from you to help us out.
First, give all of the steps on our Troubleshoot Slow Game or App Downloads on Xbox One page a try. If that doesn’t help you out, please post back with your Region, your internet provider, and a screenshot of the advanced settings page for your network here: Settings > Network > Advanced. We’ll be able to pass that information along to the appropriate people and work on getting this resolved.
It looks like the problem is big enough for Microsoft to notice but they haven’t mentioned when the problem will be fixed, and why is this happening.
On the other hand, Xbox Live status page is reporting all is well across the board at the time of this writing. Do you have any speed issues at your end? Let us know in the comments.