Last night, social news aggregator Digg.com sent a message to its publisher community confessing that its recent site redesign had got off to a “bumpy start.” That’s a pleasant way of describing the huge backlash the service has seen from its users. How has the service actually fared since undergoing its makeover?

While Digg admits it has “experienced a dip” in overall traffic, according to a new report by Hitwise Intelligence, that explanation is quite the euphemism. Since the end of August, Digg’s traffic has plummeted 26% in the U.S. and 34% in the U.K. That adds up to nearly a third of its visits lopped off, which is a bit more serious than just a “bumpy start.”

“The Internet can be a fickle creature, but if there is one lesson that seems to consistently ring true it’s this: don’t alienate your core users,” writes Robin Goad, research director for Hitwise U.K. “It’s a lesson that Digg.com is learning the hard way. Having been a paragon of social bookmarking with over 40 million unique visitors a month at its peak, there has been a huge exodus of traffic thanks to an unpopular redesign which irritated a legion of faithful power users.”

The question now becomes: How many more users is Digg willing to sacrifice before it decides the redesign was a failure? Requests for comment to Digg were not immediately returned, but in the

company’s email yesterday, Digg hinted that traffic was beginning

to rebound.

Of course, redesigns for popular services often face backlash. When Facebook redesigned its site last year, the makeover was met with widespread criticism. One thumbs-up thumbs-down poll of nearly 800,000 Facebook users found that about 94% disliked the new layout. And when Microsoft launched the now-infamous Windows Vista, critics universally panned the “upgrade,” with the vast majority of users sticking with XP.

However, for a true platform–a social network as large as Facebook, or an operating system as dominant as Windows–most users are unlikely to switch to a different service due to objections over redesigns. They have too much invested in sticking with it. But Digg isn’t the only fish in the sea: There’s a slew of services out there that serve as a worthy replacement, such as Reddit. Are the site’s users patient enough to wait for improvements and bug fixes?