I think this is unfortunate, because we might want to export something else as observable, and it's a bit confusing for people at times I imagine:

import { observable } from 'rxjs';

console.log(observable); // symbol

We're currently exporting our copy of Symbol.observable as observable from the main module. I think we should rename it, remove it, or move it under something else.

Options:

1. Export it as observableSymbol or OBSERVABLE_SYMBOL
2. Don't export it at all, and advise people to use a package like symbol-observable
3. Export it as a static property of Observable or something. like Observable.SYMBOL. (minimal overhead there, it's more of stylistic thing, I'm not saying I like it. Just an option)
4. ???? Something else.

In all cases we'd have to leave the observable export for the duration of 7.x, and simply deprecate it.