As someone who has personally touched about 200 Priuses spanning 2004-2013, I can say that oil burn is an issue on almost all of them to varying degrees. The worst I've encountered is a 2005 with 260K miles on it. 3-4 qts of oil between changes. So bad, it fouled/clogged the cat 80k miles prior.
My 2008 burns oil at a slightly higher rate than my wife's 2007, but that's more about the driver.
Yesterday, I encountered a 2009 with 150K miles - 1 qt/oil change
Today, a 2010 with 175K miles that burns about 1.5 qt/oil change
It's highly correlated to the driver/conditions. Aggressive driving or suboptimal conditions (heat/hills) and use of "B" mode on a regular basis all equate to higher oil burn.
More simplistically:
lifetime 50+ mpg = low oil burn
lifetime 45-ish mpg = moderate oil burn
lifetime 40-ish mpg = high oil burn
Best? Lady that has an '08 with 180K on it gets 50+ mpg all the time... she babies it. Stays at or just below the top mark.
Me? '08, 175K, 38-40mpg... 2 qts between changes.
EDIT: drive TYPE also matters. Lots of stop and go = oil burn. Steady cruise and constant power burn far less.