miro@miro-ntb:Downloads$ cat partlist.txt 
/dev/sda1 "f75b104c-678e-4f80-a618-70d4bf4a3ede" /
/dev/sda3 "hsjsd675-678e-4f80-a618-70d4bf4a3ede" /home
/dev/sda2 "psb8767c-678e-4f80-a618-70d4bf4a3ede" /boot

miro@miro-ntb:Downloads$ cat fstab.txt 
#
# /etc/fstab
# Created by anaconda on Mon Feb 14 16:03:26 2011
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/VolGroup-lv_root /                       ext4    defaults        1 1
UUID=10cb97f9-e52e-472b-a20b-c1e90c6d561b /boot                   ext4    defaults        1 2
/dev/mapper/VolGroup-lv_swap swap                    swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
HHH     /home  smthn defs 0 0

miro@miro-ntb:Downloads$ awk '
NR==FNR{a[$3]=$2; next} #store uuids in assoc. array
{ #on each line from fstab
for(i in a) { #loop through array
  if($2==i)  #check whether mountpoint is the same
  {$1="UUID=" a[i]} #replace 1st field with UUID=uuid
}; 
print $0;  #print the whole line
}
' <(sed -e 's/\r//' -e 's/"//g' partlist.txt) fstab.txt  

#
# /etc/fstab
# Created by anaconda on Mon Feb 14 16:03:26 2011
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=f75b104c-678e-4f80-a618-70d4bf4a3ede / ext4 defaults 1 1
UUID=psb8767c-678e-4f80-a618-70d4bf4a3ede /boot ext4 defaults 1 2
/dev/mapper/VolGroup-lv_swap swap                    swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
UUID=hsjsd675-678e-4f80-a618-70d4bf4a3ede /home smthn defs 0 0