I know that most mainstream wireless hardware lacks the throughput or capacity of a wired network. I fully understand the downsides a/b/g/n wireless and I know that cables aren't going anywhere anytime soon, especially as they bring gigabit to the desktop more routinely. That being said, I just really like wireless.
I spent this morning converting the front office of our high school to wireless (PCI cards with a decent Netgear wireless access point) to accommodate some major renovations. Obviously, our front office can't be offline with school starting in two weeks and wireless on the desktop makes moving, reconfiguration, and network planning a piece of cake. In fact, the cost of the hardware I purchased was very close to the cost of electricians rewiring the office with no significant performance hits and, in this case, no downtime.
The iMacs we're installing for teachers in the elementary and middle schools? Wireless. The teachers can now better deal with space constraints (and there are always space constraints with 25 3rd graders running amuck) by situating their computers around power sources and not the single Ethernet jack placed 15 years ago.
Besides, have you ever pulled cable? Sometimes it's necessary: I just pulled a couple of new homeruns through a ceiling (tiled, not drop...ugh) to upgrade the Internet connectivity for our terminal servers. Wireless doesn't have any place in an application like this and probably won't for a few more years (or several more years for that matter). However, I'm seeing fewer reasons to tether our remaining desktops and deal with the time and hassle associated with wired connections for most of these computers.
One caveat: don't cheap out on access points. Leave the $39.99 WalMart wireless routers for home users. Buy some decent access points, hook them up to a solid wired backbone, give them all the same SSID for easy user roaming, and enjoy.