Update to my previous post (for OSX 10.5 users only):
Replace steps 3 onwards with the following steps:
3. Open Print & Fax.
4. Click the Add Printer button (+)
5. In the window that appears Set "Protocol" to HP Jetdirect - Socket. "Address" should be set as the IP address of the printer. "Queue" can be left blank. "Name" Konica Minolta 2300DL.
6. "Print Using" Click on "Select a driver to use". Scroll down to "Konica Minolta Magicolor 2430 DL". Click on "Add". Select any options you have added to the printer then click "Continue". You have now successfully set up your printer.

Works extremly well. thanks for this! (10.5.3 + 2300DL)

Another update:
Those instructions will work with Leopard, however I have recently installed Snow Leopard (OSX 10.6) and I have found it slightly different to set up now.
In Snow Leopard to connect to 2300DL through Ethernet:
1. Download and install the Minolta 2430DL drivers (Yes, 2430DL).
2. Go into Print and Fax - click on the + to add printer
3. Select Konica Minolta magicolor 2300DL - Bonjour
4. Set the location as the IP address that is assigned to your 2300DL (eg. 192.168.1.248)
5. Print using - select printer software - select the Konica Minolta 2430DL from the drop down list - click ADD
6. Select any installable options you have fitted to the printer - Click Continue
7. You are now done. Print a test page.

Hope this clears things up for Snow Leopard users.

Another way to get this Minolta QMS 2300DL working on OS X 10.6.3

from http://www.openprinting.org/printer/Minolta/Minolta-magicolor_2300_DL you'll find detailed instructions
http://foo2zjs.rkkda.com/

note: you do need to compile it, but it worked perfectly. (use curl instead of wget or browser to download .tar.gz file)