Ubuntu 11.10 supports multiarch so you can install both 32 and 64 bit
applications, but if you do an upgrade then it will upgrade 32-bit to
32-bit and 64-bit to 64-bit. You might try to re-install applications first
to 64-bit versions and then do an upgrade. It looks like a headache and I
would do a clean installation. Precise Pangolin is
still almost three months away and I would wait until closer to release
date to make the upgrade. That gives you time to consider what to do.

I think you'd be much better off doing a clean install rather than trying
to upgrade.

Personally I do a fresh install all the time less hassle its not inviting
problems

Sorry, that change takes a clean install.

Yes, I was afraid of that. When I first installed Ubuntu 64 on this thing
there were some problems. I think that was release 9. I am hoping that by
U12 they will be cleaned up. I assume the only things I will be able to
save from this install are what is in my home account?

I've been using 10.04LTS 64bit since release and it's given zero
problems - everything works and it's rock stable :-) I'll be checking
out 12.04LTS of course when it's released and switching to that with a
clean install with all that entails - worth it as far as I'm concerned
for the subsequent stability and lack of problems that upgrades can
cause. Been there, got the T-Shirt .

PW> When I first installed Ubuntu 64 on this thing there were some
PW> problems. I think that was release 9.