Before we can start using the new version, we need to make sure that everything still works and that the changes won't break existing content. With a game as complex as RuneScape this has been an enormous task, hence the gap in updates last week. Indeed key people have been working evenings and weekends as well to get it all done!
Naturally we are still working on the types of exciting updates you'd expect, but 'under the hood' upgrades like this are also essential to help us do new types of content and continue to raise the standard of future releases.
We are aiming for an update later this week assuming the rest of our internal testing continues to progress without issue. If you're wondering what it will be, do read the behind the scenes document for September. We are still planning on sticking to that schedule and releasing the updates we said we would this month. And that's in addition to the Runescript upgrade work!
Thanks for your patience!