It seems incredible but the first victim of the cannibal Firefox (25 millions of downloads) it’s Mozilla itself!
In fact, even if already released some beta version of Mozilla 1.8, there will be no more a 1.8 final release anymore.
The unexpected success of Firefox shifts the development focus from the integrated Mozilla Application Suite to the new generation of applications — the Mozilla Firefox browser and the Mozilla Thunderbird mail and news client.
BTW, support and developement over current Mozilla versions will still continue.

read the full article: Mozilla Application Suite – Transition Plan