It all boils down to networking. The more marketers you get to know and network with, the more "inside" information you learn about. Also you can try sites like jvme.com, sites like that are designed to get you in touch with fellow marketers that want to promote your products or would like you to promote theirs.
Do something sinisterly easy and rarely done. Find a marketers personal email address or im name and ask to put on their list. Not all of them are as busy as they may seem.
Sometimes you can find up and coming launched by viewing this calender. http://www.nichejunky.com/calendar Hope this helps a tiny bit.
There are tons and tons of really good products already being sold on Clickbank which haven't been discovered yet, so digging around should find you some good results as well
you can get hop links for the current product and contact support for upcoming products............................