My worry, though, is that since they mostly focus on educational stuff, TI might not feel it's urgent to release an SDK nor fix certain display-related bugs in the calculator (such as Pt-On/BackgroundOn), and I wouldn't be surprised if the SDK only came out in 2014 or 2015. I don't think the TI community should hold off software development for 1-2 years just because of that, since it would hurt the community a lot. But again there isn't much we can do when it comes to apps unless somebody comes up quickly with an app signer/compiler (I wonder if there are any plans for a CSE update in WabbitCode?)

Oh, I absolutely agree, don't wait to start writing great programs!  But, assuming the SDK is released fairly soon, it'll be better if we can avoid using unofficial names and terminology, particularly in a program like Calcsys.  In any case, there are still some serious issues that I need to deal with before it's usable, and at the moment I have two other TI-related projects (TilEm and TILP) that are a higher priority.

As for app signing, the word is that RabbitSign should work just fine if you can arrange to have an appropriate certificate installed, or if somebody somehow managed to obtain the necessary private keys.   With the current version of RabbitSign, you may have to manually specify the program type (since it doesn't recognize the .8ck extension or the 0F product code); I'm planning to release a new version of RabbitSign shortly that fixes those issues.

Really? So basically the only difference is that some BCalls and RAM areas moved to different addresses and the LCD stuff is different?

More or less, yeah.  But just like BASIC programs, most assembly programs will need a lot of modifications to make the UI work properly on the larger screen.

@FloppusMaximus what I guess you could do is wait until June then if by June there's no sign of an imminent SDK release, then start working on apps instead of waiting, in case you end up wasting your time with TI. Just take for example TI-Connect 4.0 Windows, where there were no sign of life for its release for a long while after the calc came out (although it eventually came out with no warning)

Yup.  I guess we'll see what happens in the next couple of months.  The main limiting factor, though, is always my free time.