i found in cdt partition (hexdump), this partition table description, confirmed and completed with sbf_flash tool :

Code:
CG64 - mmcblk1 mbr
xCG63 - mmcblk1p1-mbmloader.??? (128k)
xCG30 - mmcblk1p2-mbm.??? (512k) 
CG55 - mmcblk1p3-mbmbackup.??? (512k)
CG64 - mmcblk1p4-ebr.??? (1024)
xCG56 - mmcblk1p5-bploader.??? (512k)
CG31 - mmcblk1p6-cdt.bin (512k)   <--- dump show "this partition table" like a mbr
xCG38 - mmcblk1p7-pds.ext3 (4M)
CG34 - mmcblk1p8-lbl.??? (512k)
CG57 - mmcblk1p9-lbl_backup.??? (512k)
CG42 - mmcblk1p10-logo.bin (1M)
xCG41 - mmcblk1p11-sp.??? (2M)  <--- dump show "this partition table" like a mbr
CG61 - mmcblk1p12-devtree.??? (512k)
CG62 - mmcblk1p13-devtree_backup.??? (512k)
CG45 - mmcblk1p14-bpsw.??? (4M)
CG35 - mmcblk1p15-boot.cpio.gz (8M)
CG47 - mmcblk1p16-recovery.cpio.gz (8M)
CG33 - mmcblk1p17-cdrom.iso (14M)
xCG44 - mmcblk1p18-misc.??? (512k)
xCG43 - mmcblk1p19-cid.raw (512k)
CG53 - mmcblk1p20-kpanic.raw (4M)
CG39 - mmcblk1p21-system.ext3 (327M)
CG32 - mmcblk1p22-prek.??? (512k)
CG46 - mmcblk1p23-pkbackup.??? (512k)
CG40 - mmcblk1p24-cache.ext3 (200M)
xCG37 - mmcblk1p25-userdata.ext3 (1.3G)
marked ??? are partitions formats to be determined...
xCG : never seen in full sbfs

descriptions :

lbl : Linux Boot Loader (sources in motorola sdks) contains Motorola Cert. 4496 4498
system : /system folder
userdata /data folder
cache /cache folder
cdrom : cdrom iso with defy drivers (by usb ?)
pds : /pds folder ... hmm dunno exactly what it is, used by ClockWorkMod Recovery
recovery : when you boot with bottom volume button
bpsw : something compressed ??? + Motorola Cert. 4504 4506
sp : like cdt, but 3x Motorola Cert. 4496 4498 (maybe old end of file)
prek : Pre Kernel Interface, which switch to recovery mode, Motorola Cert. 4496 4498
devtree : look like /dev content, Motorola Cert. 4496 4498
devtree_backup, misc, cid, kpanic : empty

mbmloader: checks signature of mbm
mbm: verifies all other signatures before allowing the device to boot.
mbr, ebr : master boot record, extended boot record
cdt: Codegroup Descriptor Table (partition table + the kernel command line + Motorola Cert. 4496 4498)
sp seems to be a copy of cdt

(\_/)
(ಠ_ಠ
C(")(") 
Motorola Defy, Atrix and Galaxy R
AOSP - CM Defy Nightlies (jordan)
and Author of Yaffs Explorer