I have never been able to tell if I could break glass and get it back (like dirt, wood, cobblestone etc). Is this possible at all? is it possible in version 1.6.2.
With regular tools? No; once you place a glass block/pane and hit it with regular tools or your fist - it shatters and you get nothing.
However, if you have a tool enchanted with silk touch, glass blocks and panes will drop their respective item pickups (silk touch also allows you to get other fancy stuff from various blocks - like mycelium, grass, huge mushroom blocks, ore blocks, and glowstone).