Reading information from the NAIS link you provided:
1. The program is voluntary (except for certain species in Wisconsin)
2. It doesn't include rabbits
3. Personal use animals aren't included, either
Q. If a Person Raises Animals for His or Her Own Use and the Animals Never Leave the Owner's Property, Do They Need to be Identified?
A. Under the current plan, animals that never leave a premises do not need to be identified.
Q. What Species Will be Included in the NAIS?
A. The NAIS is being developed for all animals that will benefit from having a system to facilitate rapid traceback/traceout in the event of disease concern. Currently, working groups are developing plans for aquaculture, camelids (llamas and alpacas), cattle/bison, cervids (deer and elk), equine, goats, poultry, sheep, and swine
Actually, from a disease traceabilty standpoint, I really don't have a problem with this. It'll be nice to know who to blame when we all are stricken with avian flu [sarcasm/off]