Now that you mention it, I also checked easyjet against BA for a flight from London (Gatwick or Heathrow) to Nice, leaving 19th July, coming back on the 21st.
BA quoted me a fare over 500 pounds.
Easyjet quoted me a fare of 340 pounds (still staggeringly expensive).
No doubt BA, BMI and others, such as BE, are beginning to roll out some very attractive fares which I'm sure will prove popular.
I think these are targeted mostly at Easy/Go and BMIbaby, as the Ryanair market is a little different.
Will watch developments with interest!