OP: Since it's still Beta, most of the graphic settings won't still work yet so we're not sure about that. We can be sure Valve will be able to do something about that, btw in the new test build it seems optimized for low end PCs. Correct me if I'm wrong but that's what I thought.
The game is extremely well tweakable. The high video requirements come only from the high texture/model resolutions. If they made lower quality ones, they could easily make the game run on tablets and smartphones. The game mechanic is so damn simple that you could even render it on a 15 year old DOS computer (in DOS resolution of course).
Well, the game is already playable with somewhat old pc's but in all honesty you need a better system to enjoy it as you should. Not high-end, but decent. From my own experience, DotA 2 felt like 10 times better when I got my new pc.
They made low quality textures, check the test client.
My computer can barely handle warcraft3 with max middle settings, and I can play dota2 without freeze/lag on the test client (but the visual fidelity take a huge hit ^^')
I got a i3 laptop and I can say its playable but not really, laggs and looks like shit, but its still in beta, Im seriously considering to spend like 1200e for a new computer, screen, mouse/keyboard/headphones for the full dota2 epxiriance
I'm playing DotA 2 on my 4 years old hp dv3 laptop while waiting for my new pc, 800x600 all low, it's delay and spiking in combat (I hate Alchemist's Acid spray) and the graphic is terrible make you get disadvantages when playing, but np, I'm only play with friends, they will carry me and we still can win