Yikes...if your Hershey's chocolate doesn't taste like chocolate anymore read the bag.
It may not be chocolate. Cybele who runs the Candy Blog was interviewed on the Today Show.
The short of it, Hershey's who for years has billed itself as America's Chocolate has decided to go cheap instead of maintaining quality to boost their profits. They have substituted palm oil or other vegetable oils for the cocoa butter. The end result is something vaguely chocolate flavored with a chalky texture AND a somewhat bitter after taste.
You can read quite a bit of related info on the Candy Blog.
If you don't like what you tasted do like I did. Drop Hershey and note and tell them the changes suck. I'll boycott any product that says vegetable or palm oil instead of cocoa butter and buy only those that do.
I became a fan of the Candy Blog and Cybele's work through the LA Metroblogging network. Her site is one worth bookmarking and following if you have a sweet tooth.