that isn't as contradicting as it may sound .... (btw: you have misunderstood a detail of the article linked above - the 64bit kernel will arrive with snow-leo which is 10.6)
several applications (like exs, obviously the kontakt beta) work with an old trick called address extension to access more than 4GB RAM ... however this does not mean the application as such is 64bit, neither the OS is to its full extent.
even with snow-leo there will remain some parts of the OS still in the 32bit domain, but at least the kernel (and the GUI) now gets *real* 64bit.
it is often difficult for programmers to create such a *mixed domain* application since you have to take care for every part of of your app if and how it can cooperate with 32 and/or 64 bit and mimikry the respective other address space ... and audio apps are not the simpliest type of applications.
for example VE choose the not always beloved server-solution to access additional address space (eg. outside of logic) and will allow to get beyond the 4GB barrier in an upcoming version.
i'm sure snow-leo will make many things easier in the future if more and more related stuff can now move to 64bit, though most vendors will need to re-program a lot of their stuff because of the dropped 64bit carbon support.
things are not always as easy as certain marketing departments like to make us believe ;-)
christian