Ship it!
At least once a week, I throw away an array_map because it ended up looking too bloated and go with a classic foreach instead. Short Closures 2.0 without the use(...) block would've solved this problem, just 2 votes...
I wrote down some thoughts on this RFC on my blog. I think it's worth rethinking our current definition of what "an interface" is. Especially since many languages are interface default methods as their way of multi-inheritance.