A welcome addition on new features are the RSA based encryption functions. You can generate keys with 2048 bits. Those keys can be used to Encrypt and decrypt data. Also you can sign data with private key and later verify signature using public key. I would of course recommend to use 4096 bits which seems to work well. If you need different encryption options, please check our encryption plugin.
For Canvas and Container you can now specify with a Transparent property whether the control is opaque. If the control is now transparent, some optimizations can be made like not drawing controls behind, clipping the drawings and avoid flickering. Especially software on Windows and Linux will improve setting Transparent = false.
The App Identifier can now be a constant. That allows for using different identifiers for different platforms or changing the constants in a build script.
RegEx library has been updated to 8.3.3 and SQLite to 3.7.17. If you need newer versions, please contact us to provide an updated plugins in the next days.
For submitting apps to the Mac App Store, there is a need of getting away from QuickTime and QTKit frameworks. With Xojo 2013r4 the framework no longer uses QuickTime framework, but still relays on QTKit. And for the future there are plans to use AVFoundation framework, Apple's recommended way. AVFoundation is already used to play sound on Mac OS X 10.7 and newer. Until next Xojo version removes dependencies to QTKit framework, you may need to ask Apple's review people to have mercy and let your app pass review.
What is missing currently is the Xojo Cloud support. We hope to see it in 2014r1.
Of course we also expect to see news on iOS and 64bit support on the XDC in Las Vegas.
PS: Version 4 was pulled as there was a bug which causes Xojo to crash on launch for some users. But we expect soon a quick fix.