RIM showed off some of the features of its upcoming BB10 OS and after looking at the video, I have come to the conclusion that RIM took inspiration from the Nokia's MeeGo UI.
Here is the Video for you to make up your own mind...
From the video, it is obviously clear RIM got really clever in reinventing the MeeGo UI, here are a few side by side comparisons (BB10 & MeeGo) you will find interesting.
in this first image, I put the MeeGo app screen side by side with the BB10's screen, good luck figuring out which one is the N9, they are almost identical
This is the most obvious rip off from the MeeGo UI, the alarm setup page, in the video, the RIM guy talks about how you can easily set your alarm by just moving the hands on the clock, now though the interface is different, the concept is exactly the same with the N9's
There are a whole lot of MeeGo inspired stuff on the BB10, the own swipe UI (made popular by the N9) has been ported to BB10 (they have a 90degrees swipe gesture for moving apps to the background, yea so original!) and modified to make it look original, even the fonts on the BB10 have a close resemblance to MeeGo.