So in my opinion we had one minor version with JavaScript I could relate to, and now we're back to where we were. But I don't mind, I'll just avoid using it.
Anyway, I agree that Rails core has traditionally been far from the savviest of JavaScript developers, but the nice thing about Rails 3 is that they've finally achieved reasonable modularity with all the components, so there's not much pain in getting around Rails opinions anymore.
As for CoffeeScript, I'm still on the fence, but it's clear that Jeremy Ashkenas knows his JavaScript, and his work is not done out of ignorance, so I'm glad for it to get more exposure.
What is so wrong with writing idiomatic, unobtrusive JS? I personally don't care for JS syntax (compared to the beauty of ruby and haml), but that's life... JS syntax my be ugly, but it can be written elegantly.
CoffeeScript is much more like HAML/SASS in function, and while there are arguments against those in some environments (like if you need to hire a lot of designers without a dev mentality or environment), they've been proven to be very effective in practice, and I'm quite sure CoffeeScript will be the same.