SL_enable_serialconsole-3.1-4.noarch.rpm is the same as 
SL_enable_serialconsole-3.1-3.noarch.rpm except that it uses 
agetty instead of mingetty.

The other rpm's
SL_enable_serialconsole-1152-3.1-4.noarch.rpm
SL_enable_serialconsole-384-3.1-4.noarch.rpm
SL_enable_serialconsole-192-3.1-4.noarch.rpm
SL_enable_serialconsole-96-3.1-4.noarch.rpm

Are rpm's with different speed settings for the serial console
115200
38400
19200
9600
respectivly

These latest changes were by Steve Timm