This is a sandbox to understand the list-based approach as put forward by @jonasfj. Mainly targeting Webkit 533.1 in order to gain some form of rendering framerate control on android 2 devices.

RequestAnimationFrame Shim (List-Based)

// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating

// requestAnimationFrame polyfill by Erik Möller
// fixes from Paul Irish and Tino Zijdel
// list-based fallback implementation by Jonas Finnemann Jensen

(function() {

	var vendors = ['ms', 'moz', 'webkit', 'o'];
	for (var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
		window.requestAnimationFrame = window[vendors[x] + 'RequestAnimationFrame'];
		window.cancelAnimationFrame =
			window[vendors[x] + 'CancelAnimationFrame'] || window[vendors[x] + 'CancelRequestAnimationFrame'];
	}

	if (!window.requestAnimationFrame)
	{
		var timeoutId = null, currentCallbackStack = [], totalCallbacksExecutedCounter = 0, timestamp = 0;
		function animate()
		{
			var callbackIdx,
				callbacksToAnimate = currentCallbackStack,
				len = currentCallbackStack.length;

			timeoutId = null;
			timestamp = Date.now();
			currentCallbackStack = [];
			totalCallbacksExecutedCounter += callbacksToAnimate.length;
			for (callbackIdx = 0; callbackIdx < len; callbackIdx += 1) {
				if (callbacksToAnimate[callbackIdx])
					callbacksToAnimate[callbackIdx](timestamp);
			}
		}

		window.requestAnimationFrame = function(callback) 
		{
			if (timeoutId == null)
				timeoutId = window.setTimeout(animate, Math.max(0, 20 + timestamp - Date.now()));

			return currentCallbackStack.push(callback) + totalCallbacksExecutedCounter;
		};

		window.cancelAnimationFrame = function(requestId)
		{
			delete currentCallbackStack[requestId - totalCallbacksExecutedCounter - 1];
		};
	}
}());

Changelog:

• Cleared up to adhere to clean code philosophy and therefore a quicker understanding
• removed unused variable lastTime
• micro-optimisation: replace ++ with += (test @ http://jsperf.com/increment-vs-addition)