Having the same issue here, beginning around 2:49 pm CDT 26 Feb, and ongoing. While investigating, discovered that no remote calls from within WP are working, so no plugins, themes, etc., could be updated through the WP interface, though accessing those remote sites directly clearly shows they’re up and responsive. While the update attempts report only an in WP connection failure, which could be a connectivity issue between the servers, attempting to manually have Akismet check spam instead returns a 500/Internal Server Error, but as none of the software is set to auto-update and no manual changes have been made to the sites for some time, the problem has to be a server/software/permissions change of some sort on the hosting side as these were all working fine until yesterday. The problem exists on both domains I host at DH, on three diff. installations of WP. Unfortunately, no reply from support.
According to the Data Centers page on the control panel, all of mine are running on crawford on US-East. ChrisK, TeraS & artgeek, are your sites on US-West or US-East?