I've already done so, and I've got a shadowed Mickey Hand available here for download. Just replace the existing one (back it up beforehand, of course) and relaunch all your WebCore applications.
Unfortunately, this does not have a system-wide effect. In iTunes, the music store link cursor is some 2-bit variation of the Mickey Hand. Also, when invoking Exposé, you get the same 2-bit cursor when you select windows. In Mail, you get that cursor when clicking links in non-HTML messages (web addresses that Mail allows you to click, but are really just plain-text). In HTML messages, though, Mail (at least in 10.3; 10.2 Mail is not WebCore-enabled) will use the new Mickey Hand. Other artists can likely conjure up a nice, anti-aliased Mickey Hand for use in WebCore, but the shadowing almost gives it that effect.

