The MEMS market is expanding into so quickly and into so many arenas that the tiny devices will likely end up a standard tool in every engineer's toolbox. After all, if you have to have a sensor, then why use a bulky conventional approach, when you can use an ultra-small, cheaper and better performing MEMS sensor. Also MEMS actuators are starting to build in momentum. Look for MEMS actuators to start appearing in consumer electronics devices soon--starting with the pico-projector!
MEMS found biggest market for its future. Mobile sets, intelligent gadgets and safe vehicles. Recently we saw Apple with initiative of implementing gyro in iphone4, in the mean time inauspicious antenna issues in very same system which pushed vendors to put huge efforts on MEMS biz, vendors like Infeneon, ST and intel indirectly to create less power consuming more implemented and integrated SoCs. Never forget about automotive market which is currently recovering with upward shape.