The brightness hot keys problem referred to below is fixed in kernel 22.214.171.124 that is available now.
New install using the PC desktop cd of Ubuntu Hardy alpha 6.
Since the X series thinkpads dont have an inbuilt optical drive I created a live USB from the iso using the isotostick script from here. Bootup into the live environment and installation from there was faster than I have ever experienced.
What works out of the box:
No installation issues.
Compiz-fusion runs beautifully.
Sound, wireless need no additional work, thanks to Intel.
Suspend and hibernate work out of the box!
While the volume control keys work, the Fn-Home and Fn-End key combinations to change LCD screen brightness did not work. This is the bug reported in https://bugs.launchpad.net/ubuntu/+source/linux/+bug/198476 and as I mentioned there, the fix (temporary) reported in https://bugs.launchpad.net/ubuntu/+bug/172985 worked for me.
Setting up the fingerprint reader:
I got my thinkpad with the fingerprint reader, but the ease of setting it up was a pleasant surprise. Just followed the instructions here with the difference being that you dont need to add any additional repos - thinkfinger is added in the official Hardy repos.
Not working, could not fix:
Well, really nothing for now! I am happy I removed Vista (after just booting into it to update the bios drivers). After 30 mins of Vista, booting into Ubuntu seemed like moving a century into the future ! All developers associated with Ubuntu and linux can be proud of the work they have done and the product they have created. And of course, Thinkpads are made for Linux.. too bad they come with Vista pre-installed and Lenovo refused to sell me one with no OS or with an option to refuse the license and get a refund. But thats another story...