thinking about maybe switching to a mini later this year depending on what the new ones offer when they're announced.....
If that's what you are planning, wait till they are announced to be in the channel to find out what the mileage is like. You never know what new compatibility issues might arise. Remember with each new release, no Mac can run an older Mac operating system than shipped with it. So any experience we give here today may be vastly different from what you might run into in the future.
Then if people's mileage is not what you want, and it is better on the old, get a refurbished model*:
http://www.macmaps.com/usedrefurbished.html
Note, most Mac Mini users are not running Pro Tools. If you want Pro Tools experience of today, it is better to ask in the Mac Mini forum. If you like, I can ask a moderator to move this thread.