The Samsung ML-2010 is a great bargain laserjet printer. I bought it from NewEgg last year for $49 after a $50 mail-in rebate, which I quickly recieved. While it doesn't see too much more than 5-10 pages per week, I've never had to replace the toner cartridge.

Using the Splix driver, it works great under Linux, specifically Gentoo AMD64 (x86_64) in my case. Here's how you can get it to work, assuming you already have CUPS properly installed and working (most of this will apply to any distro):

Install Splix

After this finishes, you can go to http://localhost:631/, click on the Administration tab, then walk through the steps. When it asks for a PPD file, click on "Browse" and go to /usr/share/cups/model/samsung. There you will find a file called "ml2010.ppd". You may notice ml2010de.ppd, ml2010fr.ppd, and ml2010it.ppd, which respectively are German, French, and Italian translations of the driver. Use one of those if you prefer.

You should now be able to print from any CUPS enabled application. If you have trouble with CUPS, try the Gentoo Printing Guide.

Make it work with GIMP
If you've had trouble printing from GIMP, make sure you have the gimpprint compiled into GIMP by adding "media-gfx/gimp gimpprint" to your /etc/portage/package.use:

Now delete your ~/.gimp-2.2/printrc file if you've messed around with trying to get GIMP to work before. Once you start GIMP, it will detect your CUPS printers and rebuild the file. Now your Samsung ML-2010 should be working, but it didn't for me. I had to do more.

Open up or create a new image, then click File->Print. You will then see your printers listed, click on your Samsung ML-2010, then "Setup Printer". Make sure "Postscript Level 2" is selected for "Printer Model," then where it says "Command", I had to remove the raw output (-oraw) option. Mine says:

Where "Samsung_ML-2010_USB_1" is your own CUPS device name (mine is plugged into USB_1). Click OK, then "Save Settings."

Happy Printing.

p.s. The above instructions should work for any Samsung printer that Splix supports.