Honestly you haven't experienced DotA 2 till SuPa_Link plays the game. Once this lad receives a beta key and plays it the level of enjoyment goes up. It's a good deed for yourself and everyone else that's currently playing it. If you truly want to experience DotA 2 and make a difference, take a look deep down. Make the right choice ;).
I got my hands on a key as well (but no giveaways from me, sorry ;) )
I played Dota 1 a lot, and there is some major process of getting used to for me. Some of the stuff the WC3 engine provided naturally and you took for granted works differently now and feels worse / unfamiliar. Little things, like the reaction of units to your commands, cursor responses, visual feedback.
Will probably take a couple of games before I will be able to play it as smoothly as I am used to play Dota 1.
Also, I am not a huge fan of the direction they took for the graphics; the designs for the heroes and the map. They look like made from plastic or clay. Some spells look nice, though.
I experienced a TON of bugs (walking corpses changing teams, random spell effects persisting on the map) and performance issues (ingame my pc completely freaks out on lowest settings - while Skyrim runs on high settings without any problems - , sudden FPS drops, regular 2 second lag spikes) , however it seems to be specific to my system. None of my friends saw the visual glitches or experienced similar performance problems, however I heard of some other players with similar problems (most prominently being Ars-Art)
This post is sort of off-topic, but the official feedback forum refused me, so I need some place to rant :D
As for demands, my Dota 1 buddys would probably kill to get their hands on a key ;)
Would be nice to have one, but I can live without it. My connections too crap to enjoy online gaming without latency. Although I must admit in recent weeks my ping with usbnet has been excellent. No lag at all, not even with keyboard inputs.