Cliff, Dabombguyman,
You're both right. MA3 will have been written fresh from the ground up, but if one buys a program version x and then a month later program x+1 is released, one might feel agrieved about the extra cost.
However, in this case, there's no knowing, yet, of exactly when MA3 will be ready, so the comparison might not apply. After all, as a different comparison, we know that MS is working on the next version of its OS, but one wouldn't expect to receive that next version without making an extra payment, even though we know it's in development right now.
(BTW, I'm not comparing the complexity here, just the principle!
)