Max expertise has been reported at upwards of 46 expertise skill making it unreachable in conventional tanking gear at this time.
Armory Xav. 80 expertise skill which is a 20.00% reduction in dodge/parry, all of it tanking gear. He's capped. The 102.4 part is silly for warriors to strive for, possible but probably not with maxxed expertise.
Yeah, it was a necro, the expertise cap wasn't possible to reach prior to the Sunwell patch. Penguin's testing over on EJ proved the expertise cap to be 13.75% for parry on bosses, which ended up being lower than most people expected - I know I thought it was 14.5ish and several others did as well.
As for reaching uncrushable and being expertise capped, it's probably rather easy to do, I might fiddle around later and see if I can either theorycraft up a set or just swap any of my 95283 pieces around!