The languid pulsing of the insertion-point cursor when editing text is an aspect of Mac OS X that has bothered me for years, but bothered me to such a tiny degree that I never bothered to find out if there was a way to fix it.
But today I finally asked the oracle, and inside of ten seconds had my answer. The NSTextInsertionPointBlinkPeriod default seems to work in most Cocoa apps, Xcode included, and the value seems to be in milliseconds. So a simple:
Mac-Pro:~ mason$ defaults write -g NSTextInsertionPointBlinkPeriod 187
...and voila! No more sllloooooow hypnoooootic bliiiiiiinkiiiiiing...