I ran this update last week. Note for those who chose not to upgrade to Gingerbread, it would not let me install this update until I ran the Gingerbread update and whatever that "fix-it" update was that came out soon after. Once those updates were installed, the phone saw this security update and installed it.
I had skipped Gingerbread myself because of some of the problems I had read regarding it, and the fact that my phone was working fine with 2.2. However I thought this security update was important enough to bite the bullet. All three updates ran and installed fine, and I'm regretting that I didn't do Gingerbread earlier, because I have a noticeable increase in battery life now. The only negative I found was that Shoot Me stopped working. Everything else runs fine.