I got the Gestures using Xcode4 ($5.00 -worth it!). It's large, 5Gb to download, and 10Gb to install (used an external drive to hold it while it loaded - did this on a laptop, so hard drive space was tight).
Worked just as easy as the steps listed above. After "canceling" the user i.d. screen, another "error" message regarding iOS compatibility, came up. Just ignore that, as the deed was already done.
Disconnect and go! I've got Multitouch Gestures, yeah!
No adverse side effects so far, I'll report if any show up. (iPad 1)