Lenovo/Thinkpad W500:
Core2 Duo T9400:
4GB RAM:
ATI FireGL5700 (HD3600/RV635) - Intel GMA 4500MHD
I installed to a spare/empty 160GB drive and the installer performed perfectly.

RC1 seems to be amazingly good.

I've only found a couple of problems so far;
1/ Kdenlive hangs at 99% when rendering, I think this is something to do with 'melt' as the process remains permanently using significant resources until killed even after kdenlive has been exited.
There's some stuff on the Kdenlive forum about similar problems in the past.
It works fine in my 32bit installation.
2/ 2ManDVD warns of missing ffmpegthumbnailer
kamoso and 2ManDVD (you may need to add ffmpegthumbnailer in Synaptic) coming to 64bit. 
-p.
Synaptic shows it's not installed, but if I mark it then it says it'll will uninstall kde-multimedia and kde-multimedia-ffmpegthumbnailer

3/ devede can't be installed, as it has a missing dependancy - python-psyco - ISTR this has also been discussed elsewhere on the forum (but not resolved AFAIK).
I was testing the overall speed increase of the 64bit release by rendering some H264 videos to DVD by comparing the 64bit install with my 32bit system.
RC1 appears to be about 20-25% faster at this kind of task 32bit rendered in 51 minutes, 64bit rendered (almost

) in 41 minutes

Not to be sniffed at if previously expecting a rendering session of 10 hours.
The good news is, although I couldn't complete the rendering tests for the reasons above, the 64bit version feels faster to me on my machine.
Also, great news for me, I've been stuck with the 2D GMA4500HD for ages, as HD videos were tearing and stuttering with all the drivers for the ATI card.
When I installed RC1 I tried both cards, the Radeon HD 2000 and Later driver has improved since I last tried it and I now have my 3D desktop/OpenGL/ and all my games back, woooohoooo

:D:D
(I don't know whether this just applies to the RC1 version of the driver, I'll have to try it on my 32bit install.)
Thanks to Pinoc and all the testers/packagers for this release, it's an amazing achievement.
The speed increase and return to 3D have made me a happy bunny, and I'll be looking to replace my 32bit install soon, once I'm confident that all the minor problems are sorted.