Thanks for the info.
Obviously, no .NET obfuscator can be completely robust, because at the end of the day, the CLR still has to be able to interpret your code. As a general rule, however, the more complex your application, the less likely it is that de-obfuscators like de4dot will be able to recover your code.
We'd be really interested in having a general idea of the complexity of your application and the features in SmartAssembly that de4dot was able to reverse.
To answer your question, though, the good news is yes. In the next few weeks, we hope to be releasing a new version of SmartAssembly, which contains a beta version of a new type of obfuscation. I can't say more at the moment, but keep watching this forum for details of when it is released.