Once again you have to add a PPA to get a newer version. If Ubuntu stayed binary compatible with Debian, like aptosid, Mepis, AntiX, and others the app would be in the repos.
$ apt-cache policy openshot
openshot:
Installed: (none)
Candidate: 1.2.2-1
Version table:
1.2.2-1 0
500
http://mirrors.kernel.org/debian/ sid/main i386 Packages
Well want do you know, it is already in the Debian repos.