This tendency is even more marked with things like shampoo. This is very irritating (in every sense of the word) as the 'new, improved' formula tends to mean 'new exciting flaking skin and rashes'.

Oh yes, and food. "New improved taste" = "now we add MSG and describe it as yeast extract, you didn't need that afternoon, did you?".

The situation is even worse than that: in my experience they say "new improved taste" when nothing very substantive has changed, then quietly make a major change without fanfare.

For example, Mars confectionery going non-vegetarian a few months back, or Skips suddenly introducing tomato into the recipe.

Skips are but a dim and distant memory :(

Oh lord yes. Conditioner, with me; 'new and improved' means 'cheaper to make for us and therefore doesn't work as well'.