What's up with 64 bit Linux

[Chris Gehlker]

I tried installing 64-bit Ubuntu desktop just because I could and  
discovered:

It takes a lot longer to launch.
Firefox doesn't work, at least not out of the box.
Gnome won't mount WebDAV shares.

So out of curiosity I went to the web to find out a little about  64- 
bit OSes and this seems to be the conventional wisdom:

There are no advantages to 64-bit OSes that offset the losses from  
bigger code due to bigger pointers and integers
There are classes of  applications that can really benefit from 64- 
bithood, especially those that memory map big files.
32-bit OSes can be written to support 64-bit applications at least on  
Intel and PowerPC.

So why is Linux moving in the direction of separate 32-bit and 64-bit  
builds? Is it  just to remain portable on less popular hardware?

--
The fundamental delusion of humanity is to suppose that I am here and  
you are out there
  -Yasutani Roshi, Zen master (1885-1973)