Smalltalk failed? That's news to me.
At one point GUIs were available on but a few machines clustered around research universities and defense department installations. WIMP (Windows Icon Mouse Pointer) interfaces are now ubiquitous.
Many people forget that Smalltalk might have been the "original" open source development environment. One of the great features of most (if not all) Smalltalks is that the source code is included with the Image.
Smalltalk/80 was the first time I saw an IDE. While I'm a fan of emacs + command line for certain programming tasks, debugging under Smalltalk is a transcendent experience.
Just a few examples of some of the ideas refined in Smalltalk. What has Java given us that's new?
Don't get me wrong here... The market want's Java, and I actually kind of like Java for certain types of tasks. But when it's time to develop something new, I always prototype in Smalltalk (Squeak, actually.)