JBL's web site still shows the PRX600 Series. I couldn't find anything on their web site for a PRX700 Series.
I did find a place in Europe advertising the PRX700 series. It said the PRX712 is 1500 watts and weighs 42.5 lbs.
The PRX612M is 1000 watts and weighs 35.5 lbs.
I tried out the JBL-PRX612M against everything they had in it's class at Guitar Center today, and it sounded better than all of them to me. Louder, punchier, and didn't distort when you cranked them way up. Only 35.5 lbs also. If they are discontinuing these I'm going to buy a pair of them before they do. They were plenty loud and sounded great.