Even if the device now returns to the last used application if it is woken up within a time interval (don't remember number of seconds), the notifications/lock screen could be utilized to have a button or simple widget that is like a shortcut to maximize the last shown application. THAT would be a useful thing to have. It would be much faster than "Swipe down, ehm, where is it now, hmm, there it is, *tap*".

If this is a sort of a "feed screen", then there is hopefully some api for it to be used by the apps. For instance, the media player(s) could scroll the current song/artist name there.

A lot of system properties should be possible to enable short information texts for this screen. For instance, the IP-adress would be nice to have there (but customizable of course, enable/disable option in the "about device" or something like that).
Even applications should be able to have something customizable to be enabled for viewing there. If it is customizable by the user, it won't be cluttered down (unless user want to clutter things down).
Maybe, they could call it an "activity screen" or something like that with certain rules to it so that it doesn't become a cluttered and disorderly android widget screen. It should be part of the whole application concept, so that an application has:

* full screen view
* cover page view
* announcement/information field on "activity screen" (with possibility to turn this on or off per application).

See what I mean?

Then also, if course something should be invented for differentiating left and right swipes, not only for the now called lock screen but also for the applications screen. There could probably be other interesting uses besides choosing the ambience I think.
Why not (optionally) integrating the calendar application on one of those swipes (instead of having it launched as any other application). Alarm stuff could be integrated on such a swipe as well. There are lots of possibilities here that Jolla could embrace, once they get time and their head above the surface (pun intended).

EDIT: There is actually another possibility for this screen that I just came up with, that would fix something that I really miss. If the user on this lock screen would be able to create application groups (or folders), then if one of these groups is selected, let's say for example you click the "media apps" icon. Then the launch screen(s) could then instead get populated with the launcher icons for what that the user has placed under that category. There should be a default 'All' category of course that would make the launcher screen show everything like today.

How about that people? Jolla?