The Main differences between wiki’s and blogs according to Everything Wiki (2009), Is that "a wiki is a collaborative website which can be directly edited by anyone with access to it, where as a blog is a personal or corporate website in the form of an online journal, with new entries appearing in sequence as they are written".
In a learning context however, I would not recommend this program. Firstly the openness of the program to the public and the inability to track users updates could see the Wikispace used in unproductive and even harmful ways. With this in mind there are a number of positives to using this program. If used to develop and present a class or group project, this program would be useful as it allows for collaborative learning to occur. However, overall I believe the negatives outweigh the positives and I would not implement this program in the learning environment.
-Click on the image to view my wikispace.
-(Image courtesy of Wikispaces and Cooltext.com)