Sadly so far every cue points to conclude that Ableton IS unable to... The strange thing is that in this field when firms can't do the 64bit shift inhouse, then hire an external specialized firm to do so.
Why this hasn't happened?
Newsflash!! Just days ago Ableton extended their own developers hiring process:http://www.ableton.com/referral-reward
A process that has been up online many months already... But tech firms do not hire online so its no strange that it has been a failure.
This looks bad, really bad. It is common knowledge in tech circles that converting 32bit software to native 64bit is a rather complex task, thus just a few specialized and experienced techs are able to do it. Furthermore, switching from one core to multicore/multithread optimization is several levels more difficult for developers to accomplish, and LIVE urgently needed this years ago.
With this info, I would predict that at best, if Ableton releases Live 9 soon, it will certainly not be optimized for multicore CPUs (maybe give a 2nd thought on selling your single core 4Ghz Pentium if you still stick around) and at best Live 9 will allow for 64bit sort of faked (rushed) functioning at many stages, in other words some processes will be 64 bit native and others not but wont crush it (hopefully).
Trying to look to the bright side, if ANY level of 64 bit compatibility gets finally released, just by allowing to increase the RAM over the actual 3+ Gb limit, would suffice to run Live much better than it is now.
Also one could guess that if Ableton finally attracts and hire some idealist C++ developer, that eventually gets lucky and hits the right spots (possibly if thousand of us cross fingers, send positive energy, Give Ableton a Dance, or some other magical way) then... on the medium or long run, Live could really be able to use the fantastic CPUs, fast RAM and potent hardware already
released since 2010... Yes, -as most of us know- incredible hardware exist, no need to dream with the hardware + controllers that could be available when LIVE actually gets able to -efficiently- work on today's gear.