New Bluetooth 5 will improve old version 4.2 in many ways.
Source: www.computerworld.cz
Best improvement I see in prolonged distance, which should be 400m in direct view without obstacles. In my opinion is that quite a lot, because that means, for example, I can play music while working on garden while having PC safely in house. And that means a lot for me. I like to cut the grass with music, but all that cables and players in pockets just don't feel good.
Second biggest improvement for me is double speed. My gf like to send photos from one phone to another via Bluetooth, and now.. it just take too long (and yes, I am telling her to use other ways to transfer media - no, she likes it this way. So now the speed should be up to 2 Mb/s. Still slow, but much better.
And finally they repaired lot of bugs, added new features, which we will know at the end of this year. But just to pick some, we will be able to send more types of data together and finally into more than one device. So hopefully we got really improved technology this year!