The biggest problem with foiling is the dies , however ou can do foiling dies on the laser using high temp silicon , same as rubber stamps. you can achieve incredible detial , even better than etching methods used to make dies. Foiling is real cheap and works on many items , if you have a laser , a $200 extra inverstment isnt much money. It's hardly high tech to operate either. Silicon dies work on stuff with less than flat and smooth surfaces , but dont last as long as magnesium , brass or steel dies.
With a laser , you could for example die cut and foil acrylic etc etc - many opportunities present themselves. You can use a foiler for embossing and debossing too. Nice thing about the laser is the die cutting ability , so you can do card , vinyl stickers , papers and so on. Also great for branding cheapy items like plastic pens etc that a laser cant.
Another great application is tipping , like engrave a medallion or a product logo with the letters sticking out and use the hot foiler with a silicon pad to tip the surface with gold etc.
Foils come in a zillion colours , you can actually foil a smooth surface and laser engrave it too , kinda make your own metallic coloured material.
IMHO it's a fantastic addition. Foiling goes hand in hand with pad printing and that too is VERY profitable , espcially since you can make the cliches (the engraved or etched plates that hold the ink) with a laser.