Playing around with a Dell 13z... Calling suspend or hibernate (from KDE) works great, but on resume the wireless is almost entirely blocked, according to rfkill list. Unblocking it with rfkill unblock all does not remove hard blocks, so it stays off. Pressing Fn+antenna twice, though, first blocks everything, and then unblocks everything (which is the desired outcome), and wicd takes it over from there.

I can't find the place where it gets blocked. How can I have it unblocked on resume? And where is the hook for the Fn+antenna button?

It probably won't help, but I found that Fn+antenna (Fn+F2) generates keycode 246. It does not seem to be an acpi event: I enabled event logging (in /var/log/messages), and I see things like power button and brightness buttons being pressed, but when I press Fn+antenna I just get a bunch of lines from the kernel, something from cfg80211 about updating regulatory domain, and then a bunch of frequencies. Anyway, acpid is silent. Additionally, pressing Fn+antenna also seems to disable/enable Bluetooth, although for all I care it could stay disabled.

I suggest you to use the Network Manager, it work great in combination with suspend/hibernate, as it have direct support for them via pm-utils.

Εύρηκα! After playing with rfkill I found out that it behaves erratically when I try blocking/unblocking bluetooth. And sure enough, /usr/lib/pm-utils/sleep.d/??bluetooth* had an rfkill call to block bluetooth on sleep and unblock it on resume. The problem is, issuing either command inexplicably blocks the wireless, and the only way to fix it, as far as I can tell, is by hitting Fn+antenna.

After disabling the bluetooth hook, wireless is working on resume.