Few people that take academia serious consider Wikipedia an a priori
truth, god-given or otherwise.
I personally find WP useful for my blog, where I'll link to things that offer general concepts to readers (like "Last Glacial Maxmimum" or "Human Evolution"). WP is useful for getting a quick general concept and to locate secondary sources which cite primary. I would never cite Wikipedia unless I were using a Creative Commons photo or graphic -nor would I recommend anyone cite Wikipedia since its a tertiary source. Primary and secondary sources are preferable in any research or academic writings.
As far as the Wikipedia entry on Obama, looking at the Talk Page
, there seems to be a consensus that there needs to be something written on the Obama/Ayers connection, but they're hashing out precisely how to word it. The problem they're faced with is constant vandalism by extremists that oppose Obama at the cost of logic and rational discourse and fringe media like Fox and WorldNut Daily will exploit the curtailment and moderation of such extremists to their own ends.
In the end, there was a connection between Obama and Ayers and it did, indeed, cause a stir so it should be covered by WP. I'm betting it will be soon, but in the mean time there's no reason why they should simply permit wholesale vandalism of the page by left and right wing extremists who battle back and forth over the issue.
There doesn't seem to be, however, any support for the OP which alleges with much hyperbole that "Wikipedia is rewriting history."