Australian Standard for PFD's (AS4758)
Australian Standard for PFD's AS4758 comes into effect from the 1st July 2010.  Jackets made to the new standard will start to appear on the market over the next 6 months, however jackets made to the old standard are still available and acceptable for sale for many years. At this stage until 1st of July 2015. 
This new standard has many differences from the old, the most notable being that jackets will no longer be called PFD1, 2 & 3, there will now be 5 different levels of jackets.
The levels are:-

275N PFD

Not normally a recreational jacket and the amount of buoyancy is closely equivalent to a SOLAS jacket.

150N PFD

A new level generally to be used for recreational boating in unprotected waters. Most inflatable jackets on the market have this level of buoyancy.

100N PFD

Basically replaces the old PFD1 jacket for use in protected or unprotected waters.

50N PFD

Basically replaces the old PFD2

50N SPECIAL PURPOSE

Replaces the old PFD3