>>>  WIRELESS MAC FILTERING GUIDE
    1- ipkg install wl        (install broadcom wireless driver if not already installed. Not sure if this package is really needed. I think 'WLC' is already installed in base system)
    2- vim /etc/init.d/wlmacfilter
        |-->
            #!/bin/sh /etc/rc.common
            # The macfilter 2 means that the filter works in "Allow" mode.
            # Other options are: 0 - disabled, or 1 - Deny.
            # wlc ifname wl0 maclist "xx:xx:xx:xx:xx:xx xx:xx:xx:xx:xx:xx"
            START=47
            start() {
                wlc ifname wl0 maclist "xx:xx:xx:xx:xx:xx"
                wlc ifname wl0 macfilter 2
                }
           
            stop() {
                wlc ifname wl0 maclist none
                wlc ifname wl0 macfilter 0
                }
    3- chmod 755 /etc/init.d/wlmacfilter
    4- /etc/init.d/wlmacfilter enable        (this will create symbolic link in /etc/rc.d/S47wlmacfilter to start at BOOT)

Is there any clarity on the wl package being needed or not?

I haven't installed it, and I am running the WLAN MAC filter as described above. Since the script does not contain any references to wl, I'd think it's redundant... But you never know.

I was under the impression that MAC whitelisting was largely a waste of time, due to the ease of MAC address spoofing ...

True, but it keeps the noobs out . It's not like my 63 bit random AES key is gonna get cracked anytime soon ^_^

Why not using ebtables or iptables for MAC filtering?

Because filtering using the driver is done in hardware, from what I understand. Filterting with [eb|ip]tables uses CPU.

I accidentally ran the firstboot command and i had to reconfigure my router. So I tried the  wlmacfilter without installing  the "wl: package and it worked. So the wl package is not needed, at least on my configurations (before, Linksys WRT54-GL, now Asus WL500G-Premium).