example using animation-frame branch

fly.js

var layer = new ol.layer.TileLayer({
  source: new ol.source.MapQuestOpenAerial()
});

var map = new ol.Map({
  center: new ol.Coordinate(0, 0),
  layers: new ol.Collection([layer]),
  renderer: ol.RendererHint.DOM,
  target: 'map',
  zoom: 2
});

function quadIn(t, b, c, d) {
  return c * (t /= d) * t + b;
}

function quadOut(t, b, c, d) {
  return -c * (t /= d) * (t - 2) + b;
}

function quadInOut(t, b, c, d) {
  if ((t /= d / 2) < 1) {
    return c / 2 * t * t + b;
  }
  return -c / 2 * ((--t) * (t - 2) - 1) + b;
}

function flyTo(destination, resolution, duration) {
  var origin = map.getCenter();
  var x0 = origin.x;
  var y0 = origin.y;
  var dx = destination.x - origin.x;
  var dy = destination.y - origin.y;

  var resOrigin = map.getResolution();
  var maxRes = Math.max(resolution, resOrigin) * 1.05;
  var up = maxRes - resOrigin;
  var down = maxRes - resolution;
  var upTime = duration * (up / (up + down));
  var downTime = duration - upTime;

  var start = (new Date).getTime();

  function stateGenerator() {
    var dt = (new Date).getTime() - start;
    var more = dt <= duration,
        x, y, r;
    if (more) {
      x = quadInOut(dt, x0, dx, duration);
      y = quadInOut(dt, y0, dy, duration);
      if (dt < upTime) {
        r = quadOut(dt, resOrigin, up, upTime);
      } else {
        r = quadIn(dt - upTime, maxRes, -down, downTime);
      }
    } else {
      x = destination.x;
      y = destination.y;
      r = resolution;
    }
    map.setCenter(new ol.Coordinate(x, y));
    map.setResolution(r);
    return more;
  }

  map.render(stateGenerator);
}