I don't think I've ever said this, but I've believed it for a long time. I think every programmer should contribute to at least one open source project. And use them of course, and answer newbie questions, and generally be involved in elevating the platforms we use.
There's been an amazing amount of that going on in the JavaScript world. It's really something. There's the web for documentation, much of it on Stack Exchange, it seems. I like W3schools, though I know a lot of people think it's cheesy. Their examples work, and they have the facts I need, and not a lot of fluff (yeah there are a few ads, but they're not intrusive).
And there's at least a good beginning for almost all the pieces you need. There are some things missing. But now it feels like a land rush, that in a year or two there will be projects covering every area of interest.
I think long-term this is how teams are going to form. I don't see teams being put together by recruiters working for investors, as much as it has been in the past.
When I meet a programmer, one of the first questions I ask, after asking what languages they use and what platforms they work on, is what open source projects they contribute to.
A few thoughts off the top of my head.
I think we really need a good River of News aggregator for Node. I plan to work on that. And a better way of browsing S3 structures. The tools we have there are really inadequate. The Amazon web interface is full of gotchas. We could do so much better there, imho.
I would also love to find someone to work with me on a reincarnation of Share Your OPML. It solves a huge problem for the blogosphere. And it's the kind of thing that should definitely be open source.
PS: Dave Briggs says "not just for programmers," and of course I agree.