Most companies your lucky to get a version a year maybe. Use vbulletin as an example. That It like 3 years to get vbulletin 3.5 out the door and well over a year for 3.6
2.42 was release about a year ago and then 2.5 which was a major overhaul with new features was released in February. The last couple releases of our Reviewpost and Classifieds lines have been unequaled in the amount of featured added.
I can not say what the new version will or will not have.