As a SEO you can benefit from Social Media activities and it even seems key according to Matt Cutts recent video on SEO in 2011. However besides getting 'inbound links' from third party websites or blogs as a result of people that have noticed e.g. your Twitter Tweet or Facebook Post you will, most likely, also receive links from the social media pages itself.
Now, when talking about 'link-value' would Googlebot consider a link from a Social Media page the same value as a link from a website or blog?
Please note: It goes without saying that I understand that the page must be publicly visible, not restricted by e.g. htaccess, should be lacking no-follow tags and that in case an url is shortened it should be done by applying the appropriate redirect. The question is solely about the valuation of a link published on a social media platform.