From the Technion Institute in Israel - one of the most original, creative and fun videos I've ever seen.
From Aish.com we've got "What Makes Rosh Hashana Beautiful" based on a song by One Direction.
UPDATE 9-12-12: The Maccabeats have released a cute Rosh Hashana greeting card video, featuring members of the group whistling the well-known Yomim Noraim niggun as they prepare for the Yom Tov!
UPDATE 9-13-12 - Also not a music video, but a great performance of "Chadesh Yameinu" by Shlomo Katz along with Rabbi Lazer Brody.
UPDATE 9-19-12: From Rabbi David Sirull of Augusta, Georgia, we have "Because It's Rosh Hashanah! A Musical Greeting"
Disclaimer: The following videos feature women singing.
The Ein Prat Fountainheads are back with a new video for Sukkos called "Livin' in a Booth" based on Bruno Mars "Marry You."
UPDATE 9-12-12: Apparently, the Fountainheads have released a 2nd version of their video, "Livin' in a Booth." The music is the same, but there are different video segments/the video is cut differently. The 1st version is no longer accessible by searching on Youtube - but can be reached via a link, which I happen to have in the paragraph above ;)
The Jewish Agency in France has a video based on Carly Rae Jepson's "Call Me Maybe" entitled "Call Me Maybe - Chana Tova." I'm not sure what the lyrics mean since I don't know French. Also, apparently "ch" is used instead of "sh" in French.
While not a music video, WonderingJew presents a humorous video called "Yetzer Hara"
In terms of meaning and uplifting impact - I still think nothing can top "Book of Good Life" released by the Maccabeats this time last year...
If anyone has found any other music videos for Rosh Hashana, please post them in the comments and I'll update this post.