Evidently hell must be frozen over and pigs can now fly, because the government of Japan has, finally, given its blessing to casino development.

Suffice to say it has been a long time in coming. Indeed, I have been hearing about Japan being on the doorstop of casino legalization since the 1990s, when I was a senior writer for International Gaming & Wagering Business. I can’t tell you how many times while covering gaming news from Asia you would hear something along the lines of, “…and I hear Japan is seriously considering legalizing casinos.” After all, Japan was supposed to be Macau before Macau—a land where no stigma is attached to wagering, where nascent demand and a pro-business government would combine to create a truly dynamic casino marketplace. And to that point, the Japanese Legislature has reportedly been debating casino enabling legislation since 1999, which has to be some sort of record, even compared to the tortured casino legalization process here in the U.S.

But after decades of frustration, Japan’s Diet passed an IR (integrated resorts) promotion bill last month—a measure that was originally submitted in 2013, ostensibly to help support the 2020 Tokyo Olympics effort, and had been a political football since. The reported reason for its surprise, last-minute acceptance: tourism is becoming a bigger factor in Japan’s overall economy, and by far the largest group visiting the country is middle-class Chinese, whose propensity to gamble is well known.

So far, scant few details have been made available about the measure, with specifics such as number of licenses, tax structure and operating restrictions to be ironed out in an implementation bill scheduled for next year. Most observers seem certain that, at least initially, a limited number of large-scale integrated resort licenses will be offered in major metropolitan areas.

In a note to investors, Alex Bumazhny, senior director of gaming, lodging and leisure for Fitch Ratings said, “We expect restrictions similar to those in Singapore, as there was considerable concern among some lawmakers regarding problem gambling. We expect the limited number of licenses and the potential operating restrictions to limit the total market potential relative to Japan’s large and relatively wealthy population base.”

Whatever the ultimate reasons for passage and potential restrictions, the gaming investment community remains bullish on Japan-based casino potential, with initial estimates of market size topping off in the $30-$40 billion range.

“For the investment community, Japan is seen as the crown jewel of Asian gaming development outside of Macau,” Grant Govertsen, research analyst at Union Gaming, told the New York Times. “It would be shocking if Japan doesn’t become the No. 2 market in Asia on an overnight basis.”

It is expected a who’s who of the gaming industry will line up for a chance to win one of the IR licenses. Companies expected to be interested include Macau powerhouses such as Las Vegas Sands, Wynn Resorts and Melco Crown Entertainment. Strong regional players such as Genting Group, as well as MGM Resorts International and other U.S. gaming giants also figure to toss their collective hats into the ring. Some observers predict these gaming operators will have to partner with Japanese companies to be considered for IR licenses.

“To us, the opportunity is thoroughly Japanese and thoroughly delicious,” Wynn Resorts Chief Executive Officer Steve Wynn told Bloomberg.

I understand all the excitement but forgive me if I am not ready to celebrate just yet. The earliest any Japan IR is expected to open is 2023 and, with previous experience as a guide, that leaves plenty of time for Japan to surprise and confound us yet again.