It's important to emphasize something: iCloud will always be "backdoored", by design, and backing up to iCloud is what most users should and will be doing. The reason iCloud data will always be accessible by Apple, and thus governments, is not because Apple wants to make it accessible to governments. It's so that Apple can offer customers the very important feature of accessing their own data if they forget or otherw…
One of the "knock it out of the park" features of icloud is that it lets you trivially share photostreams (It's the one service that I've found close to flawless) - so all those shared pictures are still available to the family who you shared them with should you pass away. I certainly don't know if Apple should, without a court order, share any of my data that I haven't explicitly shared with next of kin if I passed…
The problem with requiring explicit sharing is that a lot of people don't realize they need to do it to properly navigate these future events. Just look at how many people fail to write wills. You wouldn't want real-world assets to automatically get destroyed because you failed to write a will, even though there may be some things in there you didn't want to pass down. The "failsafe" mechanism there is, a court figures it out. So that's apparently what Apple is doing.
But keep in mind this is not just about next-of-kin. It's also about the ability for you to recover your life if you forget your password. That is why Apple will always have a "backdoor" into iCloud.