In the near future in geological terms, perhaps within the next 20,000 years, Yellowstone will blow. However, it is not likely to happen within our lifetime or even withing the lifetime of our great great great great great grandchildren.
No one knows and there is probably no way to know with current technology. However, we do know the really huge Yellowstone eruptions occur about every 600,000 to 800,000 years and the last one was about 640,000 years ago. Therefore, based on probability, within the next 150,000 years, very likely there will be another huge eruption, but not very likely in next 1,000 years nor in the next 10,000 years.