Regardless of the validity or otherwise of the charges he faces in Sweden, the whole thing has now descended into a political game. Ecuador most likely made that request knowing full well that Sweden couldn't produce any assurances, and that as a result they'd have a perfect excuse to do what they wanted to do anyway. Asylum has been granted purely to stick two fingers up at the USA and, to a lesser extent, the UK.
Quite why anyone believes that Assange stands a better chance of being deported to the USA from Sweden than the UK is beyond me.