As far as longevity, it's hard to say. 10 years used to be a pretty standard guess. In speaking to some colleagues about these new, lightweight uniforms, I've been told to expect more like 6-8 years.
Midway through year 2, I don't notice any excessive wear with our uniforms or anything that would lead me to believe they won't hold up for a while. That being said, I certainly plan on keeping a close eye on them for the next few years and making a pretty serious evaluation in years 6 and 7.