I am thinking about buying a 3800, using ethernet to hook into router. On my network i have a desktop PC using XP and a macbook pro using OSX 10.4.8.

I had a look at Eric Chan's page and couldnt see anything directly relating to cross-platform use.Is this set up easy to use and are there any known issues to be aware of?

I haven't tried it myself, but I believe that this will work, as long as the two computers aren't trying to print at the same time.

is there a mechanism in the drivers to allow queing across the network?

The printer is Network ready - Two or two hundred print jobs can go to the same printer ip address and the printer will automatically queue them up in the order received - that is how all network printers operate. There is a small (64Mb) print buffer in the printer, but since print jobs, especially photos and especially batch printing can be very large, you cannot rely the internal print buffer to store your job while it's waiting to be completed. Just don't shut your computer off until the job is completed. Of course while waiting, your PC can do anything else you want - work in Photoshop, queue up another print, open excel or powerpoint, emails, etc. While waiting and even while the job is being uploaded to the printer, the PC activity (CPU) usage will be minimal so you pretty much forget about it as if it has been completed - just leave the PC on.