TechNet Wiki

The TechNet Wiki is a library of information about Microsoft technologies, written by the community for the community. Whether you write code, manage servers, keep mission-critical sites up and running, or just enjoy digging into details, we think you will be at home in the TechNet Wiki.

Here Articles Posted By one can be commented by others and also can be revised by others and Can see the History of Revisions of all the Articles. So every Article will be worked on betterment each time some one go through the article.

More on this on

http://social.technet.microsoft.com/wiki/contents/articles/695.wiki-about-technet-wiki-en-us.aspx


MSDN Blogs

MSDN Blogs is Microsoft's blog site where many of its employees blog to a public audience. It has both individual blogs and product or feature-related blogs. The main page aggregates all posts in the various blogs.

The blogs accept comments and criticism from the public, which are usually not censored.
This is according to Wikipedia

As per the Forum Comment in,

http://social.technet.microsoft.com/Forums/en-US/tnfeedback/thread/b15c0faa-60ea-4c9d-bef2-a155bb89e46d/

Non-MS folks cannot create a blog on TechNet Wiki.

Conclusion.

MSFT Employees can Create MSDN Blogs
Others Can Blog out in Technet Wiki (Which can be revised and commented by MSFT and Others too)

Hope it helps for someone looking out for a difference.

Cheers,

ManjunathRV