I can see my realm (kind of) and was able to connect long enough to download one world .... but I can't play (timeout with "Fetching Realm Information" most of the time) and at least once got an "expired" message despite it being a renewing subscription.
If this was a free service then it wouldn't matter but it is a paid service and it isn't working and there has been no communications about it (why not post an error message that means something?). Before Realms, I used a server - paid $1 more per month than Realms but fewer restrictions and better availability.
During the extended outage, my realm was due for auto-renewal. iTunes says I have a current active subscription. My realm says it is expired and offers the opportunity to take out a second subscription for the same realm.
It appears that the subscription was collected BUT not applied so the realm is expired.