Hi,
I checked with my colleague working on the DSP.
The marketing guys will try to find such info.
If I will receive more info I will update this post.
However I don't think there is direct drop-in replacement.
You can switch to 56F83xx or 56F802x/3x DSC, but it brings more modification in your code and boards.
How long it stays in production I dont know.
It depends of the quantity you need.
May be you must contact your Freescale Distributor to have more details.
Pascal