The next version of WordPress is due out before the end of the year. You might assume that a wildly successful program like WordPress would automatically just "pop out" a new release at its appointed time.
Alas, even WordPress is developed by mere mortals. Consider this candid post from a WordPress developer:
We've had some unexpected big bugs (widgets, etc). We've had some people get sick. We've had some people traveling. Or moving. Or having kids, a job, a family, a life. It happens.
It's a great post. When WordPress 3.3 comes out (a little late), millions of downloaders won't give it a second thought. Of course the new WordPress came out. You, on the other hand, will have read the whole post, and gotten a glimpse of how much work it takes to keep great software going. The upgrade will be a little bit more than just a necessary evil.