Here's an update on Natty 11.04 just before Beta 2 arrives.

First, some background on Ubuntu 10.10.
My Dell 1545 has a Broadcom wifi which requires a wl driver.
This driver is supplied as source in Ubuntu 10.10.
Once compiled, initramfs must be updated. The intramfs
update operation concludes with an error of some sort.
Even so, the wireless works just fine.
One may also note later, that on bringing in an additional
new programs via synaptic that initramfs updates
never come to a graceful end. This description is very
similar to that of Ubuntu bug report 562312, which has many
'duplicates'. Most of these are Nvidia driver problems;
I never ran across another Broadcom complaint.

This problem was never solved in Ubuntu 10, but carried
forward to Ubuntu 11, but is now recognized as 'critical'.
I was able to eke out a quite usable LiveUSB made from
the LiveCD version of Ubuntu 10.10 on a 2 Gb SanDisk.
I am afraid that even with a 4 Gb USB, I have been unable
to create a reliable Ubuntu 11.04 from either its
LiveCD or directly from the LiveCD iso. The 11.04 problem
is both more subtle and more dire to encounter. In 11.04,
it would appear that with even minor post-initial-install
changes, the persistent store boundary is eventually
breeched such that what may have succesfully booted
several times before is suddenly no longer viable.
It would appear that Bug 685017 may be the Ubuntu 11
name for this problem, but even this new bug's description
leans on that of Bug 562312 for its explanation.

I have come at a Ubuntu 11.04 install from a variety of
directions, all with the same ultimate disappointment
of an eventually un-bootable USB. Before each of
these catastrophes, I've noted that virtually all the
nits I originally complained about concerning the included
applications have been satisfactorily solved.

I've got my fingers crossed that the two Bugs mentioned
will be killed before 11.04 is declared final.