While a great deal of success on the stock market is related to luck, there is some knowledge still required, and professional Wall Street analysts undoubtedly have more knowledge and experience dealing with stocks than myself or a random person on the street. They are also more likely to have heard rumors of mergers, staff changes, or other information related to upcoming events that could greatly impact a company's stock price.
Wall Street analysts' opinions on which stocks to invest in are made by some very smart people. From what I understand about it, the analysts' job is to look into this stuff daily and give reports on it. If the analysts' give false reports, i'm sure there are consequences. Not many people can afford to loose their jobs these days, so I would think they would give honest reports and try to build that trust with people investing and their boses.
Sometimes when it comes to media sources, such as TMZ for example, you need to take what you see and read with a grain of salt. That being said, I find the Wall Street to be a very reliable source for information, so yes, I would trust their opinions on the subject.
They only way I trust them is if they are suggesting mutual funds which I can look at myself and see how diversified they are. I think analysts opinions on individual stocks are way to risky to listen to. They could be paid to endorse or actually shorting the stock themselves.