I'll be sad if it really is being discontinued 'cause I've been thinking about trying it out and I'm afraid I'll fall in love with it an never be able to find it again (except on ebay of course, where I'll be forced to pay $30 for it hehe)
The only means of consumers accessing the discontinue list is if a MAC employee were to type out and post the whole thing (which is long because it contains all discontinued products ever made) or to have an employee show you at the counter.
Yes, brill, saddle, goldmine, and chrome yellow are being discontinued. I'm not terribly surprised about chrome yellow, as brights are the hardest for the company to sell overall.
The others I am guessing are due to new colors being produced that are too similar, lack of sales, etc.