Mergers and acquisitions are not unique to the videogames industry. What makes the last couple of years different is the number, size and calibre of the independent studios that Microsoft have expressed an interest in acquiring. I cannot think of anything remotely like such consolidation in any other industry.
You don't have to look too far back other than the PC gaming industry of the 90's and 2000's.
CUC (Vivendi Games) went on a purchasing spree. They bought Sierra Online, Blizzard, Massive Entertainment, among others. Sierra Online alone was 1.5 billion USD in 1996. That was absolutely gigantic at the time. Somewhat amusingly in that same deal they also acquired Davidson & Associates who owned Blizzard entertainment, that was combined with the Sierra Online acquisition for a total of 1.8 billion USD.
Considering the size of the PC market at the time that's roughly the equivalent of MS (in the current games market with a publisher publishing on multiple platforms) acquiring a publisher that's larger than Bethesda and smaller than Activision Blizzard in terms of impact to the gaming industry. It sent seismic shockwaves through the PC industry at the time. Sierra Online was not a small publisher at the time, they were one of the big boys (in terms of publishing clout in the 90's probably similar to or higher than UBIsoft today).
Let's not even go into EA's massive consolidation of the gaming industry. They put MS to shame with their history of acquisitions. Origin, Westwood Studios and all of Virgin Interactive's NA operations, Bullfrog, and a whole host of prolific developers. From 1994 to 2012, they purchased a minimum of 1 publisher or developer a year with some years having 3-4 acquisitions during that timeframe.
The acquisitions in the 1990's were particularly hurtful to the PC industry because there were significantly fewer games developers than exist today so each acquisition impacted the games industry significantly more than anything MS has done up to this point. The Activision-Blizzard acquisition, however, likely trumps any previous single gaming industry acquisition that I can think of.
I fully expect to see more acquisitions by Netease, Tencent, MS, Sony, and others as AAA games publishers and developers attempt to get out of the game publishing/development industry due to rapidly increasing cost of development (both in USD and time). If they can't find a buyer, I fully expect we'll see some developer closures and potentially even a publisher or two going bankrupt.
Regards,
SB