I don't think it's too trendy, though none of us can predict the future. If anything it will always make a great layering piece.
Anyway, at this point, I think anything goes. Fashion from this decade has been all over the place. There is always something for everyone, which makes it much easier to pick and choose trends. That makes me think that things will remain "in style" for a lot longer than in the past. Things from 2000 are certainly still being worn to this day and show no signs of slowing down. Everyone thought skinnies were just a trend, but they seem to be doing pretty well.
I doubt anyone will look at this blouse and say "omg, that's SOOOO 2008!" any time soon :) unless of course they are obnoxious and irritating, in which case their opinion doesn't really matter anyway.