J.C.Oliveira (12.11.12, 3:33 PM): Canon does have an SDK already:
It may need update for the new camera features though...
450D (12.10.12, 8:19 PM): SDK would be awesome. You could develop an app with a macro language that would be great for benchmarking lenses. Write a macro to put "lens A" through it's paces, switch over to "lens B" and rerun the macro. Compare results.