Thus forever is a somewhat useless timeframe.
With 40GH/s & current difficulty the odds of not finding a block in given amount of time:
1 week - 1 in 28
1 month - 1,606,584
1 year - 1 in 3,200,056,361,226,270,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 (rounded)
etc
Thanks, I was sort of joking. But since we are already beyond the 1in28 ballpark one should not discard worse scenarios out of hand.