Contemporary information is definitely preferred, and debate is welcome :)

As far as my efforts, this is the most recent information I've seen cited:

"The statistics are disheartening no matter how an entrepreneur defines failure. If failure means liquidating all assets, with investors losing most or all the money they put into the company, then the failure rate for start-ups is 30 to 40 percent, according to Shikhar Ghosh, a senior lecturer at Harvard Business School who has held top executive positions at some eight technology-based start-ups. If failure refers to failing to see the projected return on investment, then the failure rate is 70 to 80 percent. And if failure is defined as declaring a projection and then falling short of meeting it, then the failure rate is a whopping 90 to 95 percent." - http://hbswk.hbs.edu/item/6591.html