Have a look at the great circle mapper
http://gc.kls2.com/cgi-bin/gc?PATH=s...YLE=&ETOPS=120
180 minutes is not an issue anywhere other than Hawaii. US mainland is a problem but that won't be happening for awhile. Obviously, weather can complicate things but, in Asia at least, airports are plentiful and this issue just isn't goint to affect their ops.