Actually quite a few new items with potential; the new WKWebView they alluded to opens up a lot of nice possibilities for further improvements to our web reader, for example. And there's certainly a great deal we can do with Extensibility, even if it doesn't appear to support the "Define" function. Also, lots of interesting possibilities with CloudKit for various sorts of user data sharing (could finally have a really nice / transparent flashcard list distribution system, e.g.). And the Mac integration is tempting too though I'm skeptical as to whether it'll work well right away. And we can probably phase out our own Dropbox API support now that Apple is providing built-in support for accessing files from multiple file-sharing services.
Beyond all that, though, this was also a pretty clear case of Apple giving developers a lot of new reasons *not* to be cross-platform; iCloud with the addition of CloudKit is starting to seem like it might be worth embracing more wholeheartedly (using Core Data instead of SQLite for data storage, e.g.), Swift saves a lot of time even relative to the already-more-efficient-than-anything-else-we-use Objective-C... I'm finding myself drawn to the once-inconceivable idea of developing some parts of Pleco on a platform-specific way that were previously done in shared C code; a big chunk of the new flashcard stuff, for example. (there's a reason Anki is written in Python) We may be reaching a point where it's more efficient to do some things separately in Swift and in Java than it is to do them one time in C for both platforms.