Ì'm waiting for the retina iMac/display, because working without external mouse and keyboard never worked for me (and 15" is probably too small for the desktop)
I have mine on a stand, plugged to a large screen, with an external trackpad and a Microsoft Natural keyboard. The next step is to upgrade the display to 4k.
I second that. My MBPr13, while natively having a screen equivalent to the 800x1280 of the old 13, is now configured to the 1050-line display once found on the 17 inch model and it still looks great.
Once you can't see the pixels, the display becomes infinitely flexible.