Don't Wait if You Can't Wait a While
Many buyers are waiting for the 2018 Surface Pro release date before buying a new model. There is a chance that we will see a Surface Pro 5 this fall that delivers enough spec updates to introduce a new model.
If this happens, you can expect to see a 2018 Surface Pro 5 later this year, potentially in October. That's still a decent amount of time to wait for many users and it's not a sure thing.
The biggest rumors suggest that the Surface Pro 5, is actually a massive design change that is coming in mid-2019. So if you wait, keep in mind that you may be waiting almost a year for a new model.