I wouldn't have expected this: Piles of reports have appeared from users who can't get reliable connections from an Apple iPad to their Wi-Fi networks. The main problem appears to be that in a place where other devices see a strong Wi-Fi network signal, the iPad apparently only receives a weak one. This isn't just an artifact of the interface: those who run speed tests find the speed highly variable, especially compared to other devices (including iPhones) on the same network in the vicinity. Some users are also getting network disconnections and reconnections.
It's very odd for a new device with Wi-Fi from any firm to have these problems. The Wi-Fi Alliance's certification program has seemingly kept at bay major issues with new devices, by ensuring that interoperability and standards testing occurs before a product goes to market. (Apple is marketing the iPad with a Wi-Fi label, but the Wi-Fi Alliance's products database doesn't yet show a certification on file.)
Apple has posted a support note about an issue with an iPad not rejoining a network that it's already connected to which seems to involve only non-Apple simultaneous dual-band routers in which the same network name is used for both 2.4 and 5 GHz bands with different security methods (WPA on one and WPA2 on the other, for instance).
I expect given the volume of complaints that we'll see a 3.2.1 release of the iPad firmware post haste.