You dont need to sign WRT.
This will save the cost of Java signing. This follows the Widsets which does not need sigining. WRT 1.1 have a far more powerful library of functions which can access phones system functions via runtime library
This means many functions to access the phone can be made on for instance a N95 with revision 21 firmware onward.
There has been a presentation at Mount View s60 WTK presentation
The WRT Apps can be downloaded direct to any phone that supports S60 3rd Edition Feature Pack 2.
See Forum Nokia Explore WRT
There is a lots of high quality articles at WRT.
Flash content can be package into WRT see the article How to package Flash content in a Widget and has been a Wiki Feature Article.
Secure your flash content with