Nate Smith (an ex-Googler) and Brian Noguchi are the core developers of the framework, and the founders of the stealth startup Lever. "We have a stable financial base," Smith wrote on the project's Google Group. "We have a very different business model than Meteor, and we are creating a product-focused company that will continue to support the framework." Meteor, on the other hand, is being developed as the primary product of the Meteor Development Group.
It could be that there's room for both approaches. Tim Caswell, the resident Node.js mentor at Cloud9 IDE, concluded "Instead of teaching newcomers to never use these tools, I simply advise them to learn the basics first and then once they are comfortable with that feel free to experiment with these alternative tools."
Anyway, it's not a zero sum game, but one thing that will determine the success of these projects is community adoption. As Matt Asay points out, you can't buy a community with VC cash. It's early days for both communities. Meteor has a few more contributors than Derby but both projects have attracted a few contributors from outside the sponsor companies. Both have small but active mailing lists.