In theory yes.  In practice, not even close.  We've used web start to deploy our application for the past ten years and we're finally giving up on it.  We've repeatedly been bitten by signing issues, offline issues, missing desktop icons, broken file associations... all the kinds of things our customers expect to just work.  It's great for little hobby projects but just doesn't make the cut in production.

Our entire application is less than 10mb.  Not an issue to have to redownload, especially since it happens in the background automatically.

 

I took a look at the source and it was too messy for me to want to tinker with.  Plus there is the issue of what happens if the jars can't be unzipped to the tmp directory for whatever reason (you wouldn't believe the shape some of our customers computers are in). I'll be open sourcing my custom loader solution as its own project that can be used for any java projects that need to load or execute platform specific code and libraries.