MacWorld's Jason Snell has written up a quick way to force your local Windows or Mac iTunes library to upgrade all your songs to the 256kbps iTunes Match versions. If you're still syncing your iPhone, iPod touch, or iPad to iTunes via USB or via the new Wi-Fi sync, it's a quick way to get them on your device(s) as well.
While iTunes Match makes the -- often higher quality -- tracks available in iCloud, it keeps the local -- often lower quality -- track on your actual drive until you tell it otherwise. If you have thousands of tracks, that could be a long process.
Snell's tip involves creating a Smart Playlist or two and having the courage to delete all your local versions, trusting iCloud will replace them. If that doesn't scare you off, hit the link below and get your upgrade going fast.