It also has a single speaker, Wifi, a VGA resolution camera, and a 3Ah battery. The tablet measures 7.5" x 4.3" x 0.4" and weighs about 12 ounces.
Assuming that CPU spec is correct, the Sero 7LE will be using a newer and (probably) more powerful chip than the Sero 7+, which has a 1.2 GHz Rockchip RK3168 CPU. But that would appear to be the only important difference.
Hisense hasn't given any indication of when they plan to launch this tablet, but given that it is getting rather late in the year they're either going to have to launch these tablets soon or not at all. Given the glut of tablets on the market, I would bet on the latter option.
Hisense would certainly not be the first to pass on launching a new tablet.
Remember, Google hasn't dropped any hints about a new nexus 7, nor has Amazon leaked details about a new 7" Kindle Fire tablet. What's more, OLPC appears to have junked their plans for their second XO tablet, which was supposed to have shipped this spring.
With premium tablets like last year's Nexus 7 going for prices under $150, I think most of the major tablet makers have realized that there isn't much of a market - not in the US, anyway.