Q: The programming model is event driven, especially the way it handles I/O.
Correct. It uses call-backs, so any request to access the file system would cause a request to be sent to the file system and then Node.js would start processing its next request. It would only worry about the I/O request once it gets a response back from the file system, at which time it will run the callback code. However, it is possible to make synchronous I/O requests (that is, blocking requests). It is up to the developer to choose between asynchronous (callbacks) or synchronous (waiting).
Q: It uses JavaScript and the parser is V8.
Yes
Q: It can be easily used to create concurrent server applications.
Yes, although you'd need to hand-code quite a lot of JavaScript. It might be better to look at a framework, such as http://www.easynodejs.com/ - which comes with full online documentation and a sample application.
