I'm a little confused by it honestly. I mean if they intend on replacing the BX500 with it then that makes sense but they still offer the BX500 also. If you already own the BX500 there isn't much reason to upgrade, the 50 watt boost at 4 ohms is not going to be very noticeable. At 2 ohms there is a significant increase in power but I would assume if you are the guy carrying around a lightweight class D amp you probably aren't carrying around the cabs needed to utilize 700 watts at 2 ohms.
And if you don't already own a BX500 and you are looking at their site you can get the B1000 or BX1500 for just 50 bucks more.
If GK feels there isn't room for the 700RB and the 800RB and so they discontinued the 800, then how does Carvin think there is room for all of their amps in the same market?