Instagram has just announced on their blog that they've released version 4.2 on the App Store which brings with it official support for iOS 7 as well as an updated look and feel to match the new design of iOS. Even more, the new design now allows for larger image sizes all around which means better resolution, according to Instagram:
In this update you will find that we’ve increased the size of photos and videos in your feed so that they expand to the edges of your screen. We’re also happy to say that increased size means increased resolution, so photos and videos will be clearer and more vibrant than ever.
From what I'm seeing, slow motion video still isn't supported natively. Until that happens, there are workarounds to get slow motion video to work with Instagram. It isn't pretty but it gets the job done.
We aren't seeing the Instagram update in the App Store yet but if you do, let us know in the comments!