Its nice to see digital magazines and papers progressing. I think we will see a lot more of these kind of news in the future.
It'll be interesting to see what kind of curve this takes. A bit less than 10% of the 1M+ New Yorker readers is not bad. Amazon saw Kindle book purchase shoot from this kind of level to outpacing their print sales fairly quickly. Although Amazon's print sales only account for a fraction of all book sales, if Conde Nast starts getting a significant fraction of readers on digital, it could really change things.
I read GQ (which is also Conde Nast) and Esquire (which is not), and they both have similar tie-ins. I'd be excited to use them if/when I finally cave and get an iPad. On the other hand, I buy them predominantly so I'll have something to read on an airplane during the no-electronics periods, so my primary purpose is lost on it....