Damn Dave, I can't say anything but a big ol' hear hear for this. I have many times talked to clients who want to implement wireless LAN's and when I start to talk about redundancy procedures, backups, failovers, etc just give me a blank stare. Then they go on to say well management won't pay for it, etc, etc until I point out that then they can't rely on the wireless network for the critical functions they wanted me to configure it for!
I find the best way to approach this with customers is to make sure you have the 'what happens if the wireless network goes down' conversation with the management person who is paying for the solution before they decide to issue the purchase order. Often at that stage you can make a big difference to implementing a reliable solution verses something that is really just a nice to have but not used for any really critical work.
My biggest gripe in this is sales people who just pitch a hardware sale over the wall to the solutions integration engineer with no discussion on what the customer is trying to achieve. I would suggest anyone who is looking at implementing a wireless network which even potentially _could_ be critical talk to a competent wireless engineer about redundant configurations _before_ your manager signs off on the purchase.