It's sort of hard to see due to the shadow on the right side of the tire, however, as was said, roads are crowned in the middle and since we generally ride in the right lane, and make wider turns to the left, more wear DOES occur 'left of center' on our tires. In the UK, Japan, India they have just the opposite, tires wear a bit more 'right of center'.
However, that does appear to much more than I'd expect. As I have Pirelli Diablos on my 06 as well, and my rear tire has worn out as of today with just over 6K miles, I'd wager to say that the rubber compound on that part of the carcass is a bit softer and thus wearing unevenly (unless you do lots of steep banking to the left). I would continue to use the tire until it becomes unserviceable (which, if my tire is any indication, won't be much longer, LOL) as it does not represent any real danger. I called the local Suzuki Dealer and it's $123 for the THO1-M Battlax and that's what I'm going back to.