I kinda agree with the general spirit of this post, but I'll posit that there's a lot of stuff that's "old and new again." That is, things that were once new and shiny, that didn't catch on or really take off "big time" for whatever reason, but are waiting for that "second wind." Some things are just ahead of their times anyway.<p>That said, some of what excites me these days:<p>The new batch of programming languages that are coming out / came out recently: Clojure, Scala, Rust, Go, Fantom, Ceylon, etc.<p>Machine Learning, especially with the availability of a toolkit like Hadoop that prepackages scalable version of many popular algorithms.<p>Technologies for extracting knowledge (with rich semantics) from unstructured data (Apache UIMA, for example). And on a related note, things like Apache OpenNLP.<p>And I'm still fascinated with the general notion of a "Digital Nervous System" for organizations, where the IT systems are really analogous to the human autonomic nervous system. Bill Gates started hyping up that phrase back in the mid to late 90's (it existed before then, but Gates really got some buzz behind it), but nobody seems to have truly achieved that level of integration and sophistication to this day.<p>Semantic Web technologies are something I have a lot of interest in, and that still excite me as well.<p>I'm really intrigued by the possibilities of applying tools from Network Science and Social Network Analysis to different kinds of problems as well. It's not <i>strictly</i> programming related, but there's interesting stuff going on in the world of complex dynamic systems and studies of emergent behavior, that could have some impact on computing in days to come.<p>Business Intelligence, Data Mining, Multi-agent Systems, Grid Computing, Swarm Computing, Evolutionary Computation, Reconfigurable Computing, Genetic Programming, Biocomputing, and, hell, even good-old-fashioned AI stuff (logic programming, expert systems, etc) still excite me. I believe there's still progress to be made in all of these areas.<p>But, then again, I'm an old fart, so what do I know? Now <i>getoffamylawn</i> while I go play a MUD and surf Gopherspace.