I haven't seen a good way of diff'ing SSIS data. We started down the road with a DTS Compare at one point, but the mess of the file by MS means that it's hard to separate out logic from code, and even harder to display things.

Really the people I know using SSIS just treat them as a binary file. I can roll back to a version I know about, but I don't necessarily know what changed without good comments in the VCS commit.