Any Mac freaks out there?

I am strongly considering getting a new MacBook as mine is getting fairly old, the case is crumbling - quite literally - and I want to keep up with the times. (Current one is circa 2008)

Any suggestions on what might be a good choice for Development and Managing a Website remotely?

What is the current state-of-affairs for Mac Operating Systems?

Anything new coming out (e.g. Hardware or Op Sys) that I should wait for?

I'm pretty simple in my choices, and am still fairly content with my tiny 15" white MacBook, however, I would like something with a more reliable case, and maybe the newer Op Sys's have better security?