Hello IKA.
SmartFoxServer 2X is a new product in the sense that it's not based on its predecessor from a code-base perspective, but it's definitely a continuation of the SmartFoxServer approach to multiplayer gaming. We didn't overturn the philosophy of the product, in fact we extended and improved it into new directions.
If you are familiar with SmartFox you will find yourself at home with 2X. The general concepts are still there, only they have been simplified where appropriate, streamlined and extended.
In other words you'll be able to do more, more rapidly and easily.
Unless i have porely understood your SFS2x Explaination, our 1.6 SFS version is in fact destined to be frozen (or isn't it?)
We have no plans to freeze it. We will keep maintaining the 1.x version as we have always done.
Moving an existing SFS 1.x project to SFS2X is absolutely possible: on the client side the API are very similar so it's a minor work. On the server side you will have to port your code to Java if it's not written in that language already.
In closing I would like you to consider that SmartFoxServer has been going on for the last 5 years with relentless updates which has made the platform grow and expand to what it is today.
5 years in this field are almost an "era" due to the speed at which innovation moves in the IT sector. During those times we have seen monolithic web pages moving to Ajax, Actionscript 2 evolving into version 3, Flash based RIAs move to Flex and lots more.
All these passages have introduced remarkable improvements in their respective fields but they also had to break with the past, to a certain extent, in order to be free to provide that level of innovation.
I think it's inevitable. As regards SFS2X we have invested quite a lot into maintaining a balance between preserving the previous "philosophy" and breaking with the past where needed.