Here's part of their release:
In the last six months, the time people spent watching video on Instagram increased by more than 40 percent. As part of our continued commitment to video, you’ll soon have the flexibility to tell your story in up to 60 seconds.
For iOS, we’re also bringing back the ability to make videos out of multiple clips from your camera roll. To learn more about multi-clip video on iOS, check out help.instagram.com.
Longer video on Instagram begins rolling out today and will be available for everyone in the coming months. Multi-clip video is available this week as part of Instagram for iOS version 7.19 in Apple’s App Store.
This announcement proves, yet again, that video is king and is the new way consumers digest entertainment and advertising content.