Just read the threads on the slimdevices forums. There are some great posts from current and former Logitech employees. The new system is incompatible with the SB Touch. Current SB Radios can be upgraded to the new system.
They are going in a completely different direction.
Current SB does not go through the internet for streaming files on a local server, the new system requires the internet.
No random play on the new system.
The current system will be supported for some time due to consumer protection laws.
The software side may be ok for a while longer due to an active community, but there is said to be no new hardware for the current system.