i have snow leopard, 10.6.8 on my mac pro. would it make sense to wait for mountain lion in the summer vice upgrading to Lion then mountaion lion?

Nobody can tell you that. We don't yet know what the pricing will be or what kind of compatibility issues may arise. If you don't need anything in Lion right now, you can certainly wait, and if you do find the features of Lion compelling, there's no reason to wait for 6 months. Buy what you need when you need it, and don't worry so much about what's ahead... there's always something new coming soon!