What would you consider to be an upgrade? Lighter, more aero, more durable, more serviceable? Have you noticed any issues with your current wheels? How and where do you ride? Long distance, commuting, racing? Smooth surfaces, potholes, off-road?
Personally whatever you need I'd go for something handbuilt (easily serviceable) and with a higher spoke count. I've recently seen the result of a 16 spoke front wheel being in collision with a cat, and it ain't pretty. No idea what became of the cat.
I'd also recommend you read over some of the recent New Wheels threads. That way you might get some context for the repiles that may be about to come...