I posted my expierence in a new thread today (How to transfer purchased iTunes songs between accounts with iTunes Match).
-No DRM means no trouble. iTunes has been DRM free since halfway 2009. You can check this yourself. Sort by date of purchase. Go to show info. Look for file type: 'protected aac' or similar, and on the right side 'fairplay version'.At some point after june 2009, there will be a separation. Everything purchased after that time will not have drm.
You can transfer those files to your current account by starting itunes match, then select files that have icloud status 'matched'. Delete them but do NOT select delete in icloud. They stay visibile in your library. Select again and click download. They will now be downloaded under the account used for itunes match, in 256 bit quality and you are out of trouble.
-DRM (purchased before approxiamtely june 2009) and purchased on different account means mixed expierence. See my thread for a full description. Some songs will strangely enough still be matched, others won't. You can manually remove the drm, otherwise they can't be used with iTunes match. I had this last bit confirmed by apple support.
-To make a choice, use smart playlists to get a good oversight of your situation.
-If someone could tell the exact date on which iTunes became DRM free, that would be helpfull. Not the announcement at macworld but the date in practice.
