When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Unless you're suggesting a lot of 06-08 owners will run out and replace their engines, thus requiring replacement of the clutch to hold more power.
If anything dropping the manual option for 09 seems more likely given how few they sell.
Why would they introduce a new clutch and short shifter.
09 is the 4th year for the IS, and that means there will probably be some engine tuning (more power/more efficiency). I think they've realized that if they want to claim a real "sport" they need to make their manuals better...