I actually know of quite a few mixed couples in Irvine that are Asian husband and Caucasian wife. The common theme? The husband is a dentist/doctor/lawyer/businessman. What's missing?
On one particular street in Quail Hill, there are many mixed Asian couples (Japanese husband/Korean wife, Taiwanese husband/Vietnamese wife, Indian husband/Chinese wife). Same theme as above.
Irvine may not be diverse if you lump all Asians into a single category. But I don't think it will turn into Monterey Park either. I know someone who just emigrated from China earlier this year - she ended up settling in San Gabriel because there weren't enough Chinese in Irvine!