Upgrades to Windows 10 will apparently be available from July 29th.  I agree with the previous comments,  if you are using Windows 7 (which I find very stable), I would wait a while, and see what sort of reaction and bug comments arise before updating.  You apparently have a year to update for free, so there is no rush.

Some useful links:

www.dailymail.co.uk/sciencetech/article-3105621/Windows-10-release

www.express.co.uk/technology/581348/Windows-10-Release

www.express.co.uk/575844/Windows-10-Last-Definitive-Version

>> Window 8 has come to be seen as a dud...

www.pcadvisor.co.uk/3496959/windows-10-release-date-price-features