We have released SE PHP 4.9.4p3 to address issues with the package manager and licensing. This is mainly due to improvements in the marketplace. If you have issues installing plugins or themes and are using a version below 4.9.4p3, you do need to update. If you have no plans to install any plugins or themes, then you don't need to update at this time (unless you do need to install any plugins or themes, including official ones).
When will the 4.10 be released?
We are still on schedule for 4th quarter this year.
Oh, good. Since yesterday we are in the fourth quarter of 2017!!!!