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What: Shares of iRobot (NASDAQ:IRBT) have fallen over 11% today following an underwhelming earnings report that contained some unexpectedly soft forward guidance.

So what: For the fourth quarter, iRobot reported $100.7 million in revenue, and lost $0.21 per share. The company's top line essentially matched the $100.9 million top-line consensus, and the loss was smaller than the $0.34 loss per share Wall Street was looking for. However, revenue took a 23% drop from the year-ago quarter in spite of 28% growth in home robot sales, which underscores the company's continued reliance on the Pentagon for much of its money.

For the first quarter, iRobot projects revenue in the $98 million to $102 million range, and profits from zero to $0.07 per share. Both estimates come in below the Street's consensus of $110 million on the top line, and $0.06 in EPS. However, full-year guidance looks a bit better, as iRobot expects $480 million to $490 million in 2013 revenue, with between $0.57 and $0.72 per share in earnings. The revenue projection beats the Street's $477.3 million forecast, but falls somewhat below the $0.69 in EPS analysts had expected.

Now what: CEO Colin Angle points out that the Home Robots segment will grow 20% this year to make up 90% of the company's revenue in 2013. That's good news, as ground-based military robots have largely been supplanted by UAVs in the Pentagon's arsenal, particularly as the U.S. continues on its path to pull out of Afghanistan. However, with full-year EPS projected to come in line with the current year's result, despite rising revenue, it appears that iRobot's stock may be in for a flat year as it executes this strategic shift.

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Fool contributor Alex Planes holds no financial position in any company mentioned here. Add him on Google+ or follow him on Twitter @TMFBiggles for more news and insights.

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