Example:
BTC:
sudo ./minerd -a sha256d -o stratum+tcp://POOL_URL -u USER -p PASSWORD -d /dev/ttyUSBx -f 600
LTC
sudo ./minerd -o stratum+tcp://POOL_URL -u USER -p PASSWORD -d /dev/ttyUSBx -f 600
So just like the original gridseeds you will be running two separate instances of the mining software (one for BTC and one for LTC). Each can be tuned individually. Like J4bberwock said; it shouldn't be long before someone adds support to cgminer.
No one ever managed (AFAIK) to get separate instances of cgminer to run both BTC and LTC at the same time with the original gridseeds. You could only run cgminer for BTC and then had to run cpuminer for LTC when dual mining. Trying to run cgminer with gridseed scrypt support at the same time as cgminer with gridseed sha256 support would not work. The second instance of cgminer would see the port as already in use (I think...it's been a while).
One instance of cgminer utilizing both SHA256 and scrypt would be ideal but something tells me we wont see that unless Sfards changed the way the miners are accessed. There was some talk of it being worked on by third parties (with the original gridseeds) but nothing came of it.
Huh, hopefully they will implement driver into cgminer and bfgminer as soon as possible since the original minerd is a rather ancient piece of software ...
I wouldn't count on it. They will most likely only release what is already available and count on others to fill in the gaps like they did with the original gridseeds.