I'm going through my 40K right now. Interesting note, one dealer (Danbury VW/Audi) said that 40K TB replacement was no longer required. Said they just needed to "check" it. I said "Wow, I thought it was 40K replacement." He says "used to be & not too many people but us know it's not."
Not liking their service (long story, some other time) I schedule it at another dealer. We're talking about what else is going on with my car & I ask about the TB replacement. Point out that I thought there was a tech bulletin changing the replacement interval. Guy says "yep we got that one" & it says to check at 40, replace at 60 and check again at 80. "But," he says, "we just got another one that says replace at 40". Want to see them?
VWoA has covered this subject completely. So, the conservative guy I am, I'm replacing it at 40. I hope that they've gotten it straightened out by this time next year when the next one gets done (I'm doing a touch over 40K/year).
It'd be interesting to see what they'd say if your dealer got the first announcement changing to 60K and they skipped the replacement. Then it breaks at 55K and you go to get it fixed under warranty (the 100K one) and they tell you it should have been replaced 'cause of the 2nd bulletin that rescinded the first bulletin and your manual says 40 & the sticker on the car says 40 so you're tough out of luck.