A demo for Capcom and Ninja Theory's DmC will be released next week. If you're curious to see whether or not the gameplay lives up to previous series entries (excluding the pile of crap that was Devil May Cry 2), you may be interested to know it contains two missions and four difficulties.
The trial run will be focused around Limbo City, which you'll explore and eventually stumble upon the lovely Succubus. At first you'll be able to choose between Human, Devil Hunter, and Nephilim difficulty -- upon beating the demo on any of those, you'll unlock Son of Sparda difficulty.
As for the launch date of it: Tuesday, November 20 for North Americans.