It'd be a toss up, but I've been surprised by Silverlight. The recent implementation of Netflix streaming has been working without a hitch for me on Mac, and I

It'd be a toss up, but I've been surprised by Silverlight. The recent implementation of Netflix streaming has been working without a hitch for me on Mac, and I like some of the concepts they've worked into Silverlight-- most notably the dynamic language support for things like IronPython. The idea that I can code Python clientside, even .NET-ly, makes me happier. I haven't done much yet there, but it does raise my curiosity to avoid hacking around with Flex/ActionScript.