I hate to pile on with the 3800, but here goes...
When I got a printer a few years ago, I assumed I would get a 13 inch printer, because I couldn't see printing larger than 11x17 at most. After all, I rarely printed larger than 11x14 in the analog darkroom -- I think I made fewer than a dozen 16x20 inch prints in my life. But when I looked into printers, the larger 17-inch printer had much larger ink carts, and thus much lower ink costs. The price difference between the 3800 and the 2200 was about the cost of the full set of ink included with the larger printer.
So now what do I print? Mostly 8x10 and 11x17, of course. But every once in a while I go down in the basement and knock out a beautiful 16x24 inch print (on sheets of 17x25 inch paper from inkjetart.com), with no mess, no fuss, and no chemicals to dispose of. Sort of makes me want a 24 inch printer.... Oh, and I'm using Snow Leopard with no problems so far.
The first set of ink carts lasted a year or more, given that I don't print every day. New carts are expensive, yes, but the per-ml cost is so much lower than the tiny carts on the smaller printers, if you have any idea that you'll be printing more than a couple of 8x10's a month, it's probably worthwhile to consider the larger printer. (And it's really not that big -- it fits nicely on my large U-shaped desk. Once you get up to the 4800 printer, of course, that's getting pretty big.)
Good luck and happy printing.