There is already a topic on the 2. Nc3 system. Please refer to the following topic: 

http://altmax.com/cgi-local/cpf/YaBB.cgi?board=daringdefences;action=display;num...

As you will see, most people feel that ...d5 should be preferred, but the issue is whether to play it on move 2, or to wait until after 2...Nf6 because of some potential move order tricks.

Hgman, in the future, before you post a new topic, please make sure it is really "New" so we don't have 2 or more different topics on the same variation. While you may notice there are 2 current topics on 2. Nc3 ("Anti-Dutch 2. Nc3" and "Re: 1. d4 f5 can black spice this up"), one deals with the main lines while the other deals with a side-variation. The link I gave you is to the latter topic which is a more general discussion dealing with the main lines.