Technically speaking, a video is the easiest thing to achieve. You just dump a bunch of frames and that's it. Or use a video library. Anything.
Plus, it's massively distributable: It just works. You don't even need a computer.
Producing a sketch might be more challenging, since someone must set up a framework and people will have to work within that framework/coding style etc. which I believe might turn some people which would otherwise participate, away from the effort. I haven't studied what goes on on the openprocessing template, just took a quick glance at it (bit lazy here
, dunno, maybe it's worth it after all...
Regarding transitions, I'd go with anything. I like the idea of a common template as I like the unrelated sequencing. Maybe a common template would produce a more concise result: It would actually
show that this is an effort based on common grounds...
But what I believe is most important, as introspector mentioned, is to be resolute about it. To not get lost in endless discussions. To do it while it's still hot!