As noted, the presence or absence of oceans has no direct effect on the amount of energy the earth receives from the sun. However, the absence of oceans implies the absence or near-absence of water vapor, and this has some significant effects:

--Water vapor is the primary greenhouse gas in the earth's atmosphere, accounting for roughly 1/3 to 2/3 of the total greenhouse effect, which warms the earth by about 33 degrees Celsius (59 degrees Fahrenheit). The lack of atmospheric water vapor would therefore lower temperatures by roughly 15-20 degrees C (27-36 F), from its current value of about 15 C (59 F) to near or just below zero Celsius (close to 30 degrees Fahrenheit).

--However, the lack of water vapor would also mean the lack of reflective cloud cover. This would decrease the earth's albedo, increasing the amount of sunlight absorbed and raising the temperature. The earth's albedo is presently around 0.3, while the mean cloud-free albedo is about 0.15; in other words, the absence of clouds would increase solar insolation at the surface by more than 20% (the amount of sunlight absorbed at the earth's surface increases from 70% to 85% of the incoming total). A change in the albedo from 0.3 to 0.27 (a 10% decrease) would have the same effect on temperatures as a five-fold increase in atmospheric CO2. I haven't been able to find exact figures for a 50% drop in albedo, but it appears that the heating caused by the decreased albedo would more than offset the cooling caused by the loss of the water-vapor greenhouse effect.
Source(s):
http://en.wikipedia.org/wiki/Greenhouse_gas#Role_of_water_vapor
http://en.wikipedia.org/wiki/Greenhouse_effect
http://www.realclimate.org/index.php/archives/2005/04/water-vapour-feedback...
http://weblogs.sun-sentinel.com/news/weather/hurricane/blog/2009/01/earths_...
http://www-c4.ucsd.edu/gap/Documentsetc/GAP-UAV.pdf

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