Personally I don't keep to the standard. Since you can boot a kernel with any name, I am more descriptive. Currently in my /boot directory I have mandy-8.1-k2.4.18, and mandy-8.2-k2.4.18-6mdk and slackware-8.0-k2.4.18. I find it helps me to remember which kernel goes with which entry in my lilo.conf file.
When I install a new distro to test, I also copy its kernel over and rename it as something sensible. Unless I am happy with the distro and intend to keep it on my system, I will usually only name it according to the distro's name: peanut, rh, redmond/lycoris...
As has already been stated, the standard is either simply vmlinuz or vmlinuz-2.x.x. The z is because it's a compressed kernel image, and the numbers are fairly obvious. There is no reason to keep to this system if you don't want to. As with everything about Linux - it's all about choice.