It looks like they got the cart before the horse. WordPress 3.8 contains code that doesn’t play nice with the new version of Akismet. Upgrading to 3.9 fixes the issue.
Now, if you can’t access the dashboard because akismet broke everything, you’ll have to comment out the offending code.
Go to <root>/public_html/wp-includes/template.php and put // before line 331 to comment out require_once(ABSPATH.’public_html/wp-content/plugins/akismet/default.php’) or something similar.
I upgraded and it deleted the code, so I’m not sure the exact code. But, I had the white screen of death, and commented out the code, then upgraded to 3.9 fixed everything.
Hope this helps.