Boot Camp essentially consists of 2 functions.
One is the capability to provide for dual booting, doing the legwork required to get Windows to boot from the Mac EFI BIOS for want of a better description, performing the relevant partitioning etc (note you can do this yourself). This portion is really the Boot Camp Assistant part, namely an executable Mac program.
The other part of a collection of drivers for Windows systems that allows your Windows install, once completed, to gain access to all the functions your hardware has to offer, so making sure your Facetime camera works, providing a sensible (well, sort of sensible it can be argued) keyboard mapping and trackpad driver, and various other bits and bobs. For example a recent update in this area allowed bootcamp installations to not fall over and die at the sight of a Filevault 2 protexted Mac filesystem...
When an update to bootcamp is available, it could be an update to the assistant program that you won't really need once you have already installed Windows, or updates to the driver packages etc. Depending on what type of update, this may or may not increase the version number of the BC Assistant. Some are large, some are small. One Bootcamp assistant update did nothing except remove the Beta tag that it had when Tiger first introduced bootcamp. Others are very large, such as the one that provided Windows 7 drivers for all your hardware. Some are small but very important, such as the FileVault update.
You may as well update whenever you see one available. if you are worried, give it a week and see if a poo storm erupts on the internet after release.