I was mainly referring to the conference infra network, used for
presentations and such. Rather than a scattered AP layout, a
semi-point-to-point system targeted only to the critical resources
works well with 11a. If you keep attendees tethered to 2.4GHz, you
probably only need to alternate between at most two 5.xGHz channels to
cover the necessary endpoints, and can locate the APs in a less dense
As for whether presenters have 11a cards, there's the alternate
possibility of running another 11a AP in AP-client mode (inside the
conference hall) in a wired-to-wireless-to-wired sort of setup. This
could also work for a terminal room setup.
Of course, a lot of the convenience of frequency segregation will go
out the window in a few years when the final 11n document exists, as
it now looks like 11n will be earmarked for use in all three bands
(2.4GHz and both 5GHz ranges).
I'll just hope that my residential neighbors stay out of my 5GHz space
a little while longer.