This printer was remarkably easy to setup under Linux. It was something of an impulse buy after my inkjet ran out of ink... and after I clicked "Checkout" I thought to check what Google had to say about the support for Linux. There were no great success stories, so I thought I would have to fight with it for a few weeks to get it to a decent state... Surprise! It took only a few hours, of which most were me exploring the device.
I setup the printer on the network using ethernet (the wireless is nice, if I need it later... but for now it's sitting next to the router, so...) and for sanity I set it to get the same dhcp leased IP address (the lazy man's static). The Printers dialog in Fedora 14 quickly discovered the printer after I opened the Network arrow, which was really cool. I found out, via Wireshark, that it has some kind of webservice broadcast thing as well as a SNMP method of discovery... oh, and netbios. There's probably a few I'm missing... oh yes, dns-sd/avahi and LLMNR... anyway, the network support built-in to this printer really impressed me.
I actually ended up selecting IPP printers and entering the URI manually rather than choosing the automatically discovered one, which had a URI like: dnssd://Brother%20HL-2270DW%20series._ipp._tcp.local/ Entering it manually seemed to give me a few more options and even detected the toner level (well, kind of- I think the "starter" cartridge screws it up... we'll see after I print my way through it). The URI I used was: ipp://$IP/pcl_p1 and the driver I chose was "Generic PCL Laser Printer" with the Duplex option checked. And it's worked perfectly since then!! How awesome is that. I didn't even have to install any of the semi-GPLv2 software from Brother.
In short, I would recommend this printer to anyone that's looking for a full-featured (black/white and single-function) and yet not way too expensive laser printer. Especially if you can find it on sale for $79.99 like I did :-)
Update 16 Aug 2012: load nf_conntrack_snmp to auto-detect the printer in Gnome 3's printer dialog.
# echo "install nf_conntrack_snmp" > /etc/modprobe.d/brother_hl2270dw.conf