When almost 25 years ago 32bit CPUs started being used into PCs, 32bit OSes were available only to academic and large corporate data centers.
It took years to get a fully working 32bit environment on the desk and on the laps.
Nowadays, instead, almost all closed and open source OSes have a 64bit port available. What's still lacking is full native 64bit port for applications.
Well, there's nothing wrong with 32bit applications in a 64bit OS!
Skype, Acrobat Reader and Google Gears are just few among famous and ubuquitous applications that do not directly support the 64bit architectures, thanks to the ability to be run in 32bit mode.
On the other hand, a number of other equally famous applications do support it, namely Mozilla Firefox and Flash Player.
My question to you all is: why on Earth?
Is it a matter of laziness or what? Are all those applications so tightly tied to the 32bit world that a port would be imprectical?
Or is it just an "I don't care yet" approach?"