This applies to transfers from a Windows 7 32-bit machine to a Windows 7 64-bit machine.
Accessing your playlists on a new version of iTunes: What with the iCloud acting as a server and distributing your music, books, and apps to all your devices, this should have been easy but it wasn’t. The new version happily plugged into the music I’d transferred over via WET and TMPC, but couldn’t access my iTunes library, so no playlists. Using iTunes’ own facility, you can get hold of all your purchased material by authorising your new computer (you can have a maximum of 5, not including iPhone, iPod, and iPad) and then going to the store to download all your past purchases. This may take a while so brace yourself for another over-night download session. To get your playlists, go here http://www.howtogeek.com/howto/27244/how-to-transfer-your-itunes-collection-from-one-computer-to-another/ and do as it says. The whole process is likely to take a while because your new iTunes will be syncing with your entire library, and pulling in the tracks it needs for your playlists so that they are stored locally. NO TRACKS, PLAYLISTS, OR iTHINGS ARE HARMED IN THE MAKING OF THIS MOVE. So far.
As a side note, and because nobody tells you this; de-authorising all your computers – necessary if you have 5 already and some of them were decommissioned before you knew you should de-authorise them to make room – doesn’t lose you your library or purchases.
Caveat and more tips, see http://demtigerpaw.wordpress.com/it-worked-for-me-links-to-tech-tips-ive-known-and-loved/