Actually, the official recommendation has not changed for some time.

However, the The Australasian Society of Clinical Immunology and Allergy has changed its advice - to introduce between 4-6 months, but not before 4.
(from their info, with thanks to Epacris )
- There have been some suggestions that delaying introduction of foods may actually increase (rather than decrease) allergy, however at this stage this is not proven.
- There is insufficient evidence to support previous advice to specifically delay or avoid potentially allergenic foods (such as egg, peanuts, nuts, wheat, cow's milk and fish) for the prevention of food allergy or eczema. This also applies to infants with siblings who already have allergies to these foods.

Mantaray has posted a sticky with some interesting links on this also