The Wall Street Journal gave new life earlier this week to the oft-speculated rumor that Anheuser-Busch InBev (NYSE:BUD) might acquire rival SABMiller (OTC:SBMRY) in what would rank as perhaps the largest merger ever in the beer industry, surpassing the $52 billion takeover of A-B by InBev itself. Although the industry is undergoing an already intensive wave of consolidation, there are so many hurdles to this getting done that even the Journal admits such talk is routinely dismissed as "fantasy M&A."

Analysts say such a deal is possible, though a straight buyout would never pass muster with U.S. regulators because of the massive market share the combined company would control. A-B itself owns nearly half of the market, while MillerCoors, the SABMiller joint venture with Molson Coors, controls another 30% or so, and the two are responsible for nearly half the earnings the industry generates. Only through a significant bit of divestiture could this idea even be considered.

A-B had to give up its 50% stake in Crown Imports to Constellation Brands to complete the Grupo Modelo takeover, and it's facing the possibility of new antitrust allegations related to that deal. Plaintiffs' attorneys argue Constellation misled the courts over whether it would coordinate with A-B over price hikes, and while it's debatable how successful they'll be in pressing their claims, a deal like a Bud-Miller tie-up would require at least the separation of MillerCoors, possibly back to Molson.

Yet the discussion of such rumors shines a spotlight on the biggest gaps in Anheuser-Busch's business, so it's instructive to at least consider a potential deal to see not only what the brewer needs to do but where it might act absent such an acquisition.

Following A-B's announcement earlier this week that it was acquiring its once and future South Korean brewer, Oriental Brewing, it's clear the giant has its sights set on emerging markets. Asia's $258 billion market is growing at twice the rate of the rest of the world, but at slightly more than 14% of total revenue, it's not a big part of the brewer's business. However, further bolt-on acquisitions, possibly in China, could change that dynamic.

Yet Asia is only one part of a much larger picture, and it informs why takeover speculation at the top echelons of the industry are cropping up again. According to the market analysts at Euromonitor, in the last decade  global brewers generated 80% of their volume growth from Asia and Africa. While Oriental Brewing gives A-B the largest brewer in South Korea, with a 60% share, that market is fairly mature, growing at only about 2% annually for the past few years and not expected to grow much more than 1% per year going forward.

The real growth is expected to be in Africa, and that's where SABMiller would prove most attractive. It already has 38% of the market there, but also owns a 20% stake in No. 2 Castel, a privately held brewer with a 25% piece of the pie. Heineken at 18% is third, followed by Diageo, which actually sells more Guinness in Nigeria than it does in Ireland. Anheuser-Busch hardly has any presence at all on the continent.

Although analysts think A-B acquiring Heineken or Carlsburg, the No. 3 and 4 players in the global brewing market, is even less likely than a Miller tie-up because of their ownership structures, Heineken at least could give A-B the exposure it needs in Africa (Carlsburg also has virtually no exposure in Africa, either).

So even though I believe it is a fantasy to think Anheuser-Busch InBev would make a move on SABMiller, as the regulatory hurdles are just too high to surmount, I can see the brewer making more acquisitions like Oriental Brewing to plug some gaping holes in its operations, ones that need to be filled soon before rivals step in and take the most promising prospects. The M&A trend is not over yet, and A-B is not done leading the consolidation wave.