As you all know, if you pre-ordered Brutal Legend, or won a contest, you can get an early demo code. I got a code, played through the demo (twice) and now I just want to share my thoughts with you guys.
The gameplay is your basic action game. Press x to use your sword (a on xbox), square to electrify your enemies with your guitar (x on xbox). I found the guitar useful for stunning enemies, as I used my axe right after I used the guitar. You could also do some combos, but the demo didn't really go that deep into it. It all fells very satisfying, and the gore is beautiful.
There were some camera problems the first time I played it. I was too close to a wall, and the camera went right under me. The second time though, I didn't have this problem.
The presentation is great. The menus are lovely.

Hop in, babe. You know where I got this car? I made it. With the power of metal.
The dialogue is really charming and funny, and that's expected for a Tim Schafer game.
The demo didn't go into any of the RTS stuff, because it's only set in the first 20 minutes.
Overall, the demo was just a little taste of the game itself, and it tastes pretty good. The game feels polished and smooth and I can't wait for the full game to come out.