In the transition from the 2009 Georgia squad to 2010, with graduating seniors and early exits to the NFL, Georgia loses:
Passing: Starting QB (roughly 100% of passing totals)
Rushing: Lose 0%
Receiving: 9.5% of total receiving yards, 20.8% of receiving touchdowns (all from Michael Moore)
The good news is they retain 100% of rushing yards and scoring, since there were no seniors last year that ran the ball (unless you count Joe Cox's -28 yards on the season).
At first glance, those numbers seem pretty bad, especially on defense, but then you take a look at some of the competition.
For example, the Florida Gators:
Passing: Lose 3-year starting QB
Rushing: Lose 33% total yards, 46% of scoring (mostly Tebow)
Receiving: Lose 73% of yards, 64% of scoring
Passing: Lose 0%
Rushing: Lose 9.9% of yards, 6.4% of scoring (Roy Upchurch)
Receiving: 11% of yards, 17% scoring
I haven't finished running the numbers on every top 25 team yet, but I think Florida might be the hardest hit by total percentages of offensive/defensive production lost, while Alabama is seeing huge losses on defense.