I tried playing some Iron Banner and couldn't get a match, so I tried regular Crucible, and still nothing. My NAT settings and all are fine. Is this happening to anyone else?

Well, I guess I'll go explore the Moon some more.

Same problem here. Tried to go into both Crucible lists with mastrbiggy, got nowhere (actually crashed out of the regular each time). Been trying to go in alone ever since. No luck. :(

http://xbox.com/status

I think the stress test 'worked'. That or they are getting DOS'd. Ps4 is working for those with such recourse.

Social and GamingLimited
Affected platforms:

Xbox One

Xbox 360
Affected services:
Managing friends lists and tracking what friends are doing
7/26/2014 5:30:51 PM CST:
It’s come to our attention that some of you are having a tough time seeing the online state and activity of other users on your Friends list, and you can rest assured knowing that we’re on top of it! Thank you for hanging in there while we work. We’ll update you again in half an hour.

Xbox Live Core ServicesLimited
Affected platforms:

Xbox One

Xbox 360

Xbox on other devices
Affected services:
Signing into Xbox Live
7/26/2014 5:29:30 PM CST:
Xbox members, are you having trouble signing in to Xbox Live? As you read this message, we’re moving closer to fixing this issue. Thanks for your patience in the meantime. Feel free to check back in 30 minutes for another update.