No, no, no. You will lose almost everything this way. Authorizing your new Mac won't do anything for music not purchased through iTunes (for most of us, that's the majority), or your photos.
Originally Posted by
lan0.sky0 Log-in in to your iTunes account on your new Mac and then sync as normal. You'll be asked if you want to copy stuff from your iPhone to Mac (which you probably want to do) and then you should be able to continue as normal. Remember to authorize your new Mac with your iTunes account as well.