Have been doing a bit of reading about Google's much-ballyhooed Martha Graham Dance Co. animation. The first thing it brought to mind was Jules Pfeiffer's old series in the Village Voice of a leotarded modern dancer dedicating dances to spring, autumn, mergers, etc (see above). Pfeiffer meant those as satire but Google's illustrator-ish interpretation of actual Graham Co dancers [YouTube] was done with zero irony and lauded by almost every major news outlet. (It even made the AntiSpam press.)
On this page we've been joking that an animated GIF would have done just as well, assuming you had to have this pretentious sequence at all.
Where is the proof of this? The CSS sprite sheet is 312 KB - that's big.* The reason CSS sprites are described as "efficient" is they require less http requests to a server than pulling up individual image files--but a GIF also only loads once.
Yet a GIF is also a series of coded instructions to animate images loaded all at one gulp. The difference is the pics aren't on a single sheet but are stored as individual frames inside the GIF container. GIFs use compression tricks to minimize colors and avoid repeating information from frame to frame. With no developer skills to speak of I made a fairly accurate GIF of the Martha Graham animation that is 302 KB, smaller than Google's sprite page.
As for the success of Google's animation as a "cross-browser" solution (that is, legible in multiple browsers--GIFs being more or less universally read), as discussed earlier, the Google dancers had noticeable compositing artifacts and were very jerky. That's charming in a GIF but this is supposed to be a glimpse of our Super High Tech future.
What is at ultimately at stake here is forced corporate replacement of a universal, open source means of animation that almost anyone can make (GIFs) vs a type of animation that requires the coding skills of web specialists, who are mostly in the employ of big companies. Any "contest" between the two formats is going to be rigged since Google has a network of local server caches allowing its images to be loaded quickly, as opposed to a single mom and pop website groaning under the weight of image requests.
Additional reading: Martha Graham page about their dance gdoodle.
*Possibly Google's 312 KB sprite sheet could be reduced using gzip or some other compression scheme, yet it seems unlikely that image files such as png and GIF can be gzipped since they are already compressed. (Some say otherwise.) Also, not every browser "gunzips." See, e.g., http://developer.yahoo.com/blogs/ydn/posts/2007/07/high_performanc_3/. [Updated - and see below]
Data URIs (supposedly replacing CSS sprites): http://www.nczonline.net/blog/2010/07/06/data-uris-make-css-sprites-obsolete/
Hat tips to Hypothete, Wizardishungry, and drx.