It seems the chrome team simply doesn't do "releases". Chrome evolves over time, and every so often they bump up the release number, but they're not working to a release in the same way as Photoshop or Firefox. This reduces the significance of the release number, but that's just a product of the differing development model.
I'm pretty sure we are just being exposed to the internal developer versions, which don't have the arbitrary stupidity of public-facing versions. All the numbers mean is 'this build is more recent than the build you have on your machine'.
