University of Edinburgh made a research that estimates up to 37,964 planets can support life form that is as intelligent as humans. This is actually more of a calculation than a research.
The estimate took factors such as temperature and availability of water and minerals into account. It was then extrapolated in the Milky Way. I want to stress out the point that this calculation is limited to our galaxy. Hubble Telescope estimated in 1999 that there are a minimum of 125 billion galaxies in the universe. Some research numbers go up to 500 billion. It seems extremely unlikely that Earth is the only planet that inhabits intelligent life forms.
The researchers believe it will take 300 to 400 years for us to make contact with our neighbors. It is only natural to think that some of them are more technologically advanced than us. I personally expect that we will first be contacted rather than contact. Especially when you think about how much we have on our plate with wars, global warming, poverty, immense capitalism etc. Extraterrestrial research will not have a financial priority unless we solve those problems first and I do not see it happening in the near future.