With the A510, Acer has released the successor to the A500 that appeared about a year ago. However, it resembles the A200 from a couple months ago much more than the A500, aside from the fact that both are 10-inch tablets with a 1280x800 pixel resolution.
Acer was able to duplicate the robust feel of the A500's heavy aluminium chassis with the A200's plastic case. The back of the A200's chassis has a non-slip textured design, which nicely improves grip.
The A510 is about 25 grams lighter than the A200, and 2 mm thinner (1.1 cm vs 1.3 cm). It's still not a light-weight when you put it next to the competition, and few new tablets are thicker than a centimetre, but at least Acer is moving in the right direction. When you take into consideration the large battery of the A510 (9800 mAh) and the general sense of firmness, then the weight of 676 grams isn't so bad.
The fact that the chassis of the A510 closely resembles that of the A200 doesn't mean they are completely similar products. To the contrary, there are quite a few differences.