Switching from PC to Mac.. anything you wish you knew?

The retinabooks (and 13" Air to a lesser extent) are the ideal photographer's laptops, at least IMO. Also, OS X works great on laptops; it is designed for specific hardware and there are no stupid glitches with suspend, wakeup etc. For a desktop machine, things are less clear because Win7 is very reliable and easy to live with as a desktop OS, so I don't see many reasons to get a desktop Mac instead of a good and much cheaper Win7 machine.

The keyboard is somewhat different and you'll have to get used to that; the keyboard shortcuts are different than under windows. On a laptop you won't get home, end, pgup, pgdn, ins and del keys, but those functions are acheived with alt and cmd combined with cursor keys, and del is fn+bkspc. Except for the keyboard, I don't think you'll find the system all that different from windows, especially if you use Adobe software, which works the same.