Google investors should say goodbye to a projected $10 per share, according to new data from Citi.  The financial services company kept its "buy" and "Top Pick" ratings while revisiting Google’s stock today, but lowered its price target from $640 to $630.

Google’s suffered a lot of small defeats like this in recent weeks and months.  Two of our last four articles relating to both Google and money touch on estimates getting cut, in fact, with a third noting when the company’s shares sank below $500.  (The fourth just discusses how Google is using financial experts to manage its war chest.)

Also, we should note that Google’s stock is down 0.47 percent at the moment, while Yahoo and Microsoft are only down 0.13 percent and 0.04 percent, respectively, and the Dow and Nasdaq are both up.

Anyway, with regards to Citi’s announcement, Eric Savitz reported earlier today that analyst Mark Mahaney "trimmed his 2010 EPS forecast to $27.41 from $28.21, while cutting 2011 to $31.30, from $32.45.  He reduced his price target on the stock to $630, from $640.  Mahaney says the move reflects a combination of a change in FX expectations and reduced Nexus One sales estimates."

The Q&A portion of Google’s next earnings call could be a little more confrontational than usual at this rate.