One of my favorite fundamental security principles is perfectly summarized by this blog post: "Are you Secure? Prove it.
This is true for any situation more so for high severity issues like the MS08-067 vulnerability. So, one of the big names in enterprise security products came out with couple of signatures in their end user protection product. I won't name which one since it doesn't really matter in this context.
Taking into account that not all organizations can patch immediately, in large enterprises there are many factors which can contribute to the delay, the last resort to protect users is to rely on security software on their workstations. Antivirus can only go so far and it's largely useless these days. However, some HIPS signatures can limit the exposure.
So, this HIPS product rolled out signatures to supposedly detect and prevent the attack. After testing their claims it turned out that it only blocks exploit attempts from the workstation which has this HIPS installed. Any attacks against this workstation will be successful. It is beyond me why this decision was made. It'll stop the worm from spreding but it won't protect the client from being infected by the trojan which can easily be downloaded by the shellcode.
Interestingly, the response from the vendor was that they created detection for the most common exploit vector. I understand that it's not always possible to create signatures for the vulnerability, product has its limitations, thus only specific exploit vectors are detected.
But in this case it wasn't event the most common vector. My tests used the code which was published on milw0rm by stephenl and at that time had just over 10,000 views, currently at over 16,000. I would think that the vector used in that PoC would be the most common since it's quickly copied by many other hacking sites.
Thus, if organizations rely on their security vendor's claims and don't have in-house expertise to verify those claims then they're at a high risk of having a false sense of security. Considering that this product is from a rather large security vendor then the list of those organizations is rather large.
On the upside, vendor was notified and is currently working on updating their detection.