To be honest i do think its about time.
php4 has moved on to php5 mysql has gone from 4 to 5. So software is becoming more better, securer, faster and more reliable and to keep up with phpBB2 is just going to be like phpBB3 so instead of 2 versions it will just be the same.
I think people dont like moving to phpBB3 from phpBB2 is becasue the admin panel on BB3 is more complex and harder to learn although its just looking at where to go. Saying that i think if there was a mod or something for phpBB3 to make the Admin panel more like phpBB2 people would be alot happier with it. Although i wouldnt like to see the long list of links for items on the left.
but like buying a house or a car you learn from experiance, you look into how much you will benifit from it.