Per The Firearms Blog, Browning has quietly announced on its web-site that it is ceasing production of the Hi-Power pistol. There is no explanation as to why. Only that "[c]urrent dealer inventories will be the last available from Browning for the foreseable [sic] future." (See Browning's web site here).
While the Browning Hi-Power was ubiquitous in many armed forces around the world, it never gained the popularity in the United States as the Colt 1911 design. To a large part, I suspect that this was due to the historical preference for the .45 ACP over the 9 mm. Thus, while the 1911 has been modified, adapted, and upgraded by numerous manufacturers so that it is still considered a relevant design, the Hi-Power hasn't changed all that much, other than some minor changes to allow cheaper production and a short-lived attempt to produce one in the .40 S&W cartridge. And other than FN's brief attempt to directly sell Hi-Power pistols under its own name, the pistol has only been available through Browning within the United States. In short, there is not nearly the interest in the Hi-Power as there is in other designs, and its primary advantage over other semi-automatic pistols for much of its history--its 13-round magazine--has been superseded by other handguns since the 1980's. Combined with a relatively high cost when compared to other handguns, I can see why it hasn't had the popularity that it deserved in the United States, nor the staying power of the 1911 design.
The importance of the Hi-Power design, however, is its tilt barrel, breach locking mechanism which has been adopted in some way by nearly every other semi-automatic pistol designed and produced over the last 50 years.* (See also this article from American Handgunner and this article from American Rifleman). And, in that regard, the Hi-Power lives on.
* I recognize that the 1911 also used a tilt-barrel system, but the Hi-Power used an integral cam on the bottom of the barrel system, replacing the lug in the 1911 system. This has proved more popular for modern designs.