Brignacca gives us the following data from the 2005 Australian Open: In 127 matches charted, the average match winner AM was 22.5% and the average loser's AM was 11.0%.
I've only charted the AMs for the top 10 seeds plus a couple of potential spoilers (Raonic, Tomic) and Chardy, who made a run to the quarters. (I'm leaving out Monfils, as he's the outlier of outliers.) Here are the average AMs for the winners of all matches in the table and the average AMs of all losers of those matches:
Average AM of match winners: 23.2%
Average AM of match losers: 8.5%
So the these are pretty close to the 2005 averages. Since the wins were all posted by top 10 players or future top-10 players (Tomic & Raonic), we would expect the winning average to be greater than the whole-tournament winner's average from 2005, since that figure included many more early round victories posted by lower ranked players. The losses were distributed through the full seven rounds, but included the losses of 11 of the 12 quality players here under consideration (excluding the champion of course), so we might have expected the loser's average to be a bit higher as a consequence. I would generally expect the seeds to go down with a fight and post higher-than-average AMs in defeat. But this was not the case at this tournament: only 6 of the 12 (Federer, Tsonga, DelPotro, Gasquet, Raonic and Tomic) posted AMs greater than 10.0 in defeat. Interestingly, 4 of those men lost to Federer, which would seem to support the widespread pre-tournament view that he had a tough draw.
There was some talk at this tournament that the surface played faster this year than in previous years. I would say that the average AMs here do not support this view. On the other hand, many of these matches were played at night, when the courts apparently play much slower, so that may have skewed the AMs, but I'm not going to bother trying to sort that out.