Well considering the large development in terms of plugins and this is currently a BETA, we'll have to wait and see how many new features come out with ST3 to justify the 3 tag. Or it can become a Firefox and have ST18 in a couple of years.... ;-)
Might be worth pointing out that the version number is no longer on the application name. There was "Sublime Text 2" and now there's just "Sublime Text".