This patch is only 8 MB in size but it seems to have eliminated the stuttering for me. I played a couple instant action matches and one online and not one stutter whatsoever. The optimization still isn't on the level of MW2 for sure, but that annoying stuttering seems to be gone.* Friends fix for join in progress and Friends tab in server browser.
* Performance improvement for dual and quad core.
* Improved connectivity with Black Ops Rcon tool.
I looked in the new INI and sure enough the values for CPU usage were changed; the ones they had in there were much lower than the values for the MW2 config. I guess that's what fixed the issue for me, although others on the steam forums have noticed the issue is still there for them.
Did the patch fix the stutter for you? Make sure you restart steam to apply the patch.