Why 90 seconds? The FAQ explains:
Video on Flickr grew out of the idea of “long photos” and as such, we’ve implemented what might seem like an arbitrary limit of playing back the first 90 seconds of a video. 90 seconds?
We’re not trying to limit your artistic freedom, we’re trying something new. Everyone has endured that wedding video, where even the bride will fast-forward to the “good bit.” In fact, even Tara at FlickrHQ hasn’t made it past the first 90 seconds of her own wedding video.
Just try it! It’s fun once you get the hang of it.
I reckon this will bring a whole different dynamic, quite different from YouTube – videos will either be these “long photos” the FAQ mentions, or very short and snappy pieces of work. Could be good to see how people make best use of the short time available.