I am a type 2 and diagnosed just this year in June. I am 47, 185 and 5'9" tall. My bs have come way down in the last few weeks. I was at 360 when placed on Metformin. Now I average between 100 and 115 most days.
I've never really thought much about life expectancy of being diabetic until you asked. To me, it'd have to be on an individual basis. For now though, I want to think on the positive side of life and just live to the best of my ability. My days are getting better and I don't really worry as much about what I can/can't eat, testing my bs, or checking my feet everyday for possible problems.