Sounds interesting, BUT spark plugs are very very good at what they do and I think it will take a long time to get any new technology up to the same standard
In a few ways, spark plugs need massive voltages to create a spark. Lasers will no doubt use less energy which means less load on the alternator and therefore less load on the engine.
Also, igniting in more than one location in the engine could be used to promote faster flame velocities (Faster burning) and also more uniform burn which can increase power and also reduce emissions.
I'm pretty sure I read a very similar piece on yahoo 2 years ago. back then there wasn't much difference in the energy used between sparkies and the laser ones as it needed to be quite a powerful laser to ignite but it was being worked on.
they reckoned by 2012 all spark plugs in new cars would be the laser type. we shall see.
Unfortunately as you search for more power and more efficiency at the same time cost almost always increases. Fuel injection systems are a prime example and make up roughly half the cost of current hi-end diesel engines, expect injectors to cost ~£500 EACH!