This is certainly a cool surprise. It's not like people have been asking for the return of Dragon for a while.
A newsstand app certainly makes the most sense. It doesn't rely on people visiting the website for content and fits the modern paradigm of newsmag consumption. People willing to sit at a computer screen to read a magazine are likely rare, and many likely offloaded the PDFs onto a tablet anyway.
And it replaces the WotC, which was certainly not article-friendly but needed to have the generic information front for newcomers.
This feels like one of the most topical e-initiatives WotC has done. They've been behind the mobile curve for a while, launching magazines and DDI tools right before the tablet explosion.
I just wish we knew if future issues were also going to be free...