It was reported today that robotic surgery company Intuitive Surgical, Inc. (NASDAQ: ISRG) may not meet analysts average revenue expectations for 2008 and this is driving shares down $7.00 hovering around $281 per share.

Although the company guidance discussed figures around $850 million while the analysts were GUESSING $873 million temporary disappointment is affecting trading. Despite this, Eli Kammerman of Cowen & Co is maintaining his "Outperform" rating saying that he expects Intuitive to beat Wall Street expectations, and that the shares will outpace the market by 15 percent to 20 percent over the next 12 months.

So earnings might be in question, the stock is bouncing, the outperform rating is intact, and everybody still loves Intuitive -- but the stock is down so far on what is an up day. It was only a month ago I posted something similar Chasing Value: Intuitive Surgical drops on analyst disappointment after ISRG report actual earnings. If not for the analysts where would we find opportunity?

Is this a buying opportunity or signs of a week market? That answer involves more guessing, but if the stock trends down more, than it is more of an opportunity, which means you should have this world class medical device company on your watch list.

UPDATE: closing price $274.75 ,-$13.90 (-4.82%)

EXTENDED HOURS: $289.00, +14.25 (5.18%) on news that ISRG will replace Bear Stearns in the S&P 500.

Sheldon Liber is the CEO of a small private investment company and the principal for design and research at an architecture & planning firm. He writes the columns Chasing Value and Serious Money. Disclosure: I own shares of ISRG.

Until a decision on XM Satellite Radio Holding (NASDAQ: XMSR)'s hoped-for merger with Sirius Satellite Radio Inc. (NASDAQ: SIRI) is made, both companies are forced to proceed independent of one another. While wishing for the best, the companies must also prepare for the worst, should they lose their hope for synergy.

Part of the companies' continued day-to-day operations include visiting the earnings confessional once a quarter. XM's turn comes tomorrow after the closing bell. According to Zacks, the consensus analyst estimate stands at a per-share loss of 44 cents, with the high end at a 40-cent loss and the low end at a 52-cent loss. This is a decline from a year-ago loss of 32 cents, which positively surprised the Street's consensus view by a healthy margin.

As the firm heads under the earnings spotlight, the shares appear to be bottoming out from a technical perspective. After tiptoeing along the 9-10 range for several months, XMSR has broken out into double-digit territory, gaining nearly 50% since mid-August. This month, the equity has taken out its 10-month and 20-month moving averages. A monthly close atop these long-term trendlines would be the first of its kind since September 2005.