I believe it is 4GB for emmc (aka onboard flash), or at least that is what it seems from doing a df on the mounted partitions:
Code:
# df
Filesystem Size Used Free Blksize
/dev 189M 76K 189M 4096
/mnt/asec 189M 0K 189M 4096
/mnt/radio 189M 8K 189M 4096
/mnt/obb 189M 0K 189M 4096
/system 362M 338M 24M 4096
/efs 5M 36K 5M 1024
/data 2G 630M 1G 4096
/preinstall 1G 327M 899M 16384
/dbdata 71M 11M 60M 4096
/cache 299M 48K 299M 16384
/mnt/.lfs: Function not implemented
/mnt/sdcard 29G 21G 8G 32768
/mnt/secure/asec 29G 21G 8G 32768
As you can see, /data has 2GB and /preinstall has 1GB, and the last 1GB is divided up between different system partitions. So we do have 4GB, but not as an internal SD card like you guys are thinking.