The Minis are actually great machines and can be full-fledged workhorses. Again, unless your work absolutely requires you need a PCIe-card accepting Mac machine, or if you need to run high end video cards for hi-end 3D rendering applications, there is really no reason to buy a Mac Pro right now.
The new ones -- if they do (finally) come out, will absolutely blow the current ones away and will be worth it, if you are bent on getting a Mac Pro. I can't see any reason to get one at this time given the product cycle and the current level of "old tech" (2010) hardware the Mac Pro has right now.
Me: Well, I am an enthusiast, I love the Mac Pro, and I am one of those guys who digs having a "power" machine -- that's really why I have a Mac Pro. No compromise, it can tackle any job I throw at it.