Such button-down caution would have killed upstarts like eBay (EBAY) and Amazon (AMZN), and may have slowed the development and deployment of fiber-optic technology. Will the new version of Wall Street back biotech companies emerging from startup? Once upon a time, Genentech (DNA) was a shot in the dark.

The Financial Modernization Act of 1999 kicked the 1933 Glass-Stegall Act down the stairs, ending the regulatory distinction between investment and commercial banks. If the 1933 law were still in place, it would mean that JPMorgan Chase (JPM) couldn't have bought Bear Stearns, that Bank of America couldn't have saved Merrill Lynch (MER) or that Barclays (BCS) couldn't have snapped up most of Lehman Brothers. Now, it looks like Wall Street has come full circle, with Goldman Sachs and Morgan Stanley filing to become bank holding companies.

It's unclear how IPOs will be handled by Wall Street's latest incarnation - and the current market won't provide any answers.

"IPOs are the first thing to be taken off the radar when markets go sour," says Sal Morreale, an institutional salesman who specializes in IPOs at Cantor Fitzgerald.

There have been a few deals, but for the most part they're traditional companies with solid balance sheets. The reason: IPO standards go up in a wobbly market, because investors demand quality and won't tolerate much risk.

John E. Fitzgibbon, Jr., a former equity syndicate manager, author of Deceitful Practices: Nomura Securities and the Japanese Invasion of Wall Street and founder of IPOScoop.com, says little will change in the new issues market after Wall Street rebounds.

"The only thing new is the history you haven't read," he says.