a bird brought me this info:

Intel Pentium M Low Volt 1.2, 1.4 & 1.5 (758) GHz or Ultra Low Volt
1.2GHz, select models feature Intel Centrino Mobile Technology (802.11b,
802.11b/g, 802.11a/b/g (X41 only))

12.1" TFT (1024x768)

X41 tablet - PC4300 256MB or 512MB 533MHz(runs at 400MHz) DDR RAM
(up to 1.5GB supported)

60GB, or 40GB hard disk drive, 1.8" design is 13% quieter and
offers 20% more shock resistance than standard 2.5" design

X41 - Intel Graphics Media Accelerator 900 integrated graphics (up
to 128mb / integrated)

Optional IBM ThinkPad X4 Dock provides expansion and cable
management

Magnesium composite top and bottom cover

Travel weight starting at 3.5 lbs ( kg)

Longest Standard Battery Life: up to 5.7 hours (8-cell system
battery) or 2.5 hours (4-cell system battery) standard battery life; up to 8
hours with optional extended life battery

Secure Digital card slot and two USB 2.0 ports (one is IBM Powered
USB 2.0 Port)

Windows XP Tablet PC Edition models

Models with three-year warranty Battery covered by one year
limited warranty

IBM Fingerprint Reader available on select X41 tablet models

Thinnest, Lightest IBM Ultraportable ever - 1.14" thin with travel
weight starting at about 3.5 lbs

IBM Active Protection System - integrated motion sensor
continuously monitors your ThinkPad tablet to help prevent hard drive
crashes when a fall or similar event is detected.

Ergonomic ISO standard keyboard (85 keys, 18.5mm vertical and
18.2mm horizontal key pitch, 2.5mm stroke) with palm rest

New IBM Powered USB 2.0 Port allows users to attach external
optical devices without the need for a separate power adapter

Models available with up to five built-in communications
capabilities. v.92 Designed Modem, Gigabit Ethernet and Infrared standard.
Additional connectivity choices include: 802.11b, 802.11b/g or 802.11a/b/g
wireless and Bluetooth.

New Secure Digital card slot uses small and light media (as light
as 2g) with fast transfer rates (up to 20MB per second)

Access IBM button - easy access to a universe of online and
on-system resources; or customize for your corporation

IBM ThinkPad X4 Dock converts the ThinkPad X41 Tablet to a small
and light 2-spindle solution via true mobile docking power on button and
key-lock for added security

Modular, easy-loading Ultrabay Slim bay for swapping of common and
optional devices including CD-RW/DVD Combo, DVD-ROM, (devices are common
with T4x Series)

NEW! Integrated fingerprint reader on select T41 tablet models puts
your passwords at the tip of your finger

TrackPoint ("Press-to-Select" and Internet Scroll Bar)

IBM Embedded Security Subsystem standard on all models