In our Malware Removal forum here at the Spybot Search & Destroy site are many systems with reasonably current versions of Spybot S & D, antivirus and even other additional antispyware products. However, these same systems are full of spyware, viruses and trojans, many because the operating system (doesn't matter which version) hasn't been kept up to date.
Real-time antispyware and antivirus can help to protect a system from some known malware by making you aware of an attack and even by 'blocking' it in some cases. However, they still depend on the operating system to protect itself to some extent and they can do very little about new malware that aren't yet known within their definitions/detections/signatures.
Since the entire Windows 9x/ME family will no longer receive even critical security patches and hasn't had any other updates in at least two years, there are already openings in the OS that aren't protected. As time goes on, anything new that's found won't be patched at all, so the known vulnerabilities and exploits will only continue to grow.
Though someone who uses their 9x PC only offline or at their ISP site for email is probably OK with good antivirus protection by their ISP and on the PC, how long do you think the AV companies will support these older versions? Once they realize that few of those with the older OS will pay for protection, it will quickly become too costly to support. And limiting the software to allow it to run on Windows 9x is foolish, with the security and other abilities that have existed in the Windows NT family since Windows 2000.
As time goes on the ability to get support for most AV and ISP programs will disappear as those companies move forward with most of the world. My own guess is that most will declare support ended by late this year or early next, as Vista is made available to home users, since that will be time for most remaining holdouts to upgrade to new PCs. Those who won't upgrade aren't likely to spend much on either software or ISP services, so why would these companies care? Note that even though they don't directly make money from it, Team Spybot hasn't rushed to fix the Windows 95 issue that occured last year in Spybot S&D 1.4.
There isn't a magic day that everything will stop working, but this is the first situation in a long time, if ever, where an entire family of a once very popular computer product has ended support all at once. I think everyone will be surprised how quickly it will be over when there's no money to be made from supporting Win9x/ME.
Bitman
P.S. noel-pr7: have you ever tried to test the updated SpybotSD.exe that's been posted a couple times on Windows 95? If that doesn't work it would be telling to the future of 95 and even 9x support in general.