With OS X Lion, Apple challenged the accepted way of doing things by introducing new features that change the way you use a computer.
Now with all the Music that goes into your Mac, iTunes make's the Synchronizing of all your music files that much easier. So if you have an iPhone, iPad, or iPod and have a great music library on one device, then worry no more. iTunes Match will make sure only the music files you just gotta all over the show will be automatically Synced to any device. Seamlessly and with no effort on your part. It will just appear like magic on any and all Devices that you Authorize. Lovely.
If you need more drive space or just want to keep a copy of your vast image gallery or music library, the best idea is to get a back up drive or external drive and move stuff over at will. I like the Seagate brand myself. With this baby at 2TB you'll have plenty of space for a good long while.