Ubuntu 64 bit only gives you 64bit libs, so if there isn't a good 64 bit build available you can't have the app. Though there is a hacky unofficial way of having the 32 bit libs.
Is the unofficial way "apt-get install ia32-libs", or do you have something else in mind? I'm a bit thrown by the idea of unofficial as applied to Ubuntu in general, but I believe ia32-libs is even in the standard repository.
When XP64 was first released, I had a small issue with drivers, but the advantages were obvious.
I dumped the printer, got a newer one, dumped the USB Modem and went with routers and NEVER looked back.
I have not used any form of 32Bit O/S since... Well, back then.
Never had a problem with it.
What advantages were obvious? You only listed things that 32 bit operating systems can do.
There are advantages to 64 bit, but almost no consumer needs them.
That said my Windows PC is 64bit, but only because all the drivers were available. If it was going to be any harder to use 64 bit Windows 7 I would have installed the 32 bit version.
64bit ubuntu is still more work for no reward for me, so I use the 32 bit version, life is to short to be an early adopter.
You must be the only person that I have heard say it's easier to go 64bits with windows... I've been using 64bit linux for over 6yrs now, from early opteron days, and apart from flash there has never been too many problems. Early on a few driver issues on some IDE controllers (i was on scsi mostly anyways). These days flash works fine on 64bit, on linux i can't think of a reason to stay on 32bit. Unless of course you're still thinking the only advantage of 64bit is the 4GB of ram limit. 64bit x86 linux is probably better tested than x86 32bit linux.
I went windows XP 64 1yr ago and nothing worked. Everything would crash all the time, couldnt play most of my 2yr old games. Now i'm using 7 64bit and a 32bit XP VM, and it's working OK now. Actually flash on windows kinda sucks on W7 64bit.