VPN + lot's of APs + optical fiber ring = problem solved :)

Even if Meru has indeed solved QoS issues, I doubt very much that they do any better as far as security is concerned.
Any company that considers that its internal data is too valuable to risk simply cannot choose wireless as a network tool.
In other words, Meru isn't getting anywhere near banks, that's for sure.
For the rest, private industry and public administration, well security has never been a top priority (demonstrably not for the public domain), so Meru probably has a good shot there, and any other place where the sysadmin got his qualifications in a box of Cheerios.
The serious people will take care in properly evaluating the risk vs the reward. A cheap network is worth nothing if it costs you millions in lawsuits due to leaked data, or worse, the company due to corporate spying.

Maybe ppl should stop watching those "sci-fi" tv serials like "24", "Las Vegas" and "Alias" where heroes crack a remote network with a snap of the finger while running and shooting and talking via the radio...