I shamefully repost my message (tweaked) in a new topic as my question was probably not extremly visible in this thread.
I have just about the same requirement - display the discounted value in the product detail page and in the search results - and I'm interested in finding the best approach. I'm currently trying to sort all the info I find about the deprecated promotion extension, the promotion engine, discounts etc. so any help would be much appreciated.
Today I know how to create a promotion rule, action, condition and so on. At runtime I can retreive the promotion in the productpagecontroller see the promotion info but I'm afraid the promotion only applies once the product is added to the cart.
Am I condemned to parse the sourcerule action get the disocunt percentage and apply the promotion myself ? It seems kinda overkill.