I'm actually experimenting with this right now since I have a laptop and dsktop computer.
Ceni is good at finding wifi - and since it is only a script to write to the /etc/network/interfaces file, it does not have a memory footprint like wicd. The main benefit of wicd is managing multiple wireless networks (i.e. home and college campus) accessed on a regular basis; or roaming. Ceni handles roaming pretty well, just rewrites the interfaces file.
I think the real issue going forward will be how integrated network management becomes with systemd. The wpa_supplicant.conf currently needed by systemd-networkd file can be set up for multiple networks - I think the wireless connection defaults to the one with the strongest signal, but actual roaming (hotel, coffee shop, etc ..) would be kind of a pain. The /etc/network/interfaces file and wicd files are not used by systemd-networkd, so ceni and wicd are incompatible. As it stands now, one would have to write a new wireless rule(s) for systemd, or stop the systemd-networkd services and use ceni or wicd for actual roaming.
Kind of long winded, but for now, I would say wicd is still needed for those with laptops and netbooks - particularly students and professionals that travel - as it is the still the easiest to deal with.
Again, it will be interesting to see how much networking is taken over by systemd - it's actually a bit of a step backwards because the user is now back to configuring the network manually which requires knowing how to write a systemd rule.