Interesting! I sure hope that if Jagex does decide to rewrite the engine that it won't delay Stellar Dawn's release 
Just remember to mention the source, which in this case was W13 from Zybez 
They promised by 2011.
They also promised Q1 2010. Plans change.
I do hope they don't completely rewrite the system. I thought most of this would have been done with the actual re-start progress of Mechscape-Stellardawn.
On the Runefest note; there's quite a few interesting things they had for viewing at that thing.