I couldn't find the video, but I believe there are some shooters out there that have reached a practical level of accuracy shooting two pistols at a single target simultaneously.
However, in practice, such a skill is only for novelty purposes. i.e. there are far more cons than pros.
-one-hand grip less stable than two-hand grip
-can't get precise sight alignment for both pistols at the same time, when aiming both at a single target (lasers may help though)
-reduced effective range
-reduced performance for rapid fire
-slow reloads
-slow to deal with malfunctions (e.g. racking slide)
Off the top of my head, the only situation where dual-wielding pistols can be useful is when a lone soldier or cop is in a building with many hostiles. Since enemies can pop out from any direction, the soldier/cop can point each weapon in a different direction to cover critical areas; the time it takes to turn around to point a single weapon will appear to take a lifetime compared to simply turning your head and shooting using the pistol nearest the target. Obviously such a situation is VERY unlikely to occur unless you're a one-man-army living in Raccoon City, lol