I'll just get it out of the way: I'm probably wrong on all of these, and sticking them up on the wall for all to see forever is an act that screams for temporal retribution. And retribution there shall be. But first, there must be an affront to the very fabric of time. And here it is:

1. Google will continue to grow its influence over developers around the world. Their APIs, tools and services will form the beginnings of what could be called the Internet-based stack.
2. API management will be quite important. Incoming API usage will need governance, and outgoing API services will need formally enforced policies.
3. Web-based IDEs will start to make big waves. Project Bespin and the forthcoming Atlas will both change developers' perceptions of what a Web-based IDE is capable of. Call it cloud-based development.
4. Functional languages start making more headway in the United States. Europe has already figured this out.
5. Remember all that increadible optimization work that went into JVMs over the past 10 years? It will really be appreciated by all the people running Ruby, Clojure, Python and Scala. In a few years, I expect JVMs to be the standard runtime for most non-C-ish languages.