Well, in my opinion, which may be wrong...and probably is.
The new sd mod mounts the actual sd as /sdcard2/.
The problem i see with this is all the apps are looking for /sdcard/.
Now I think the best way to handle it would be to symlink /sdcard/ and /sdcard2/ as one volume.
The problem with that is that the volume manager would probably freak the **** out when you take your sdcard out of the device.
I don't know though, maybe bigrush or whoever got it working has this thought out better than I would have - but I am a software developer, not a kernel developer. That **** hurts my head.
Right now, i don't have an extra SD card worth my time of putting in (biggest extra I have is 8 gigs).
The only point I really see in it at the moment is extra space available from a file manager.
I am not sure if media scanner has to be modified to include the new directory to pic up on pictures, movies, and audio.
-HTC EVO LTE - Stock ATM
Google+: Karl Carpenter