Looks like old Banjas stock. If you have very old Celeron-M laptop (not the Dothan based Celeron), it might be worth the upgrade. Performance wise, it's not much, but if you want to use the SpeedStep to get some more juice, this might be worth it.
Jakster - unfortunately, you laptop can't get the upgrade. The chipset on the laptop probably doesn't support the Pentium-M even if it's pin-compatible.