One thing that should be discussed when talking about the "The coming RIA wars..." (That have been going on for almost 5 years) are the benefits and limitation of the underly "VM" that the technologies are built on. For any given application one VM technology made be best suited for the application requirements. A framework can make it easy to use the VM and smooth the rough edges, add features but the true benefits and limitation come from the VM itself.
Currently there are four different VM technologies people use to build RIA applications (in no particalur order).
- 1.) Java
- 3.) Flash
The article http://ajax.sys-con.com/read/232046.htm provide a good breakdown of the VMs.