I just bought a MacBook Pro and I maxed out the CPU, SSD and the RAM because these are not easily upgradable components. I opted to spend more up-front for a machine that will have a longer lifetime without running up against constraints added trying to minimize outlay cost.
Thanks for the reply bear, I likely won't be able to max out everything due to my budget. However I might be able to max ram, just wondering if you ever get past 8 gb? I know eclipse takes up a fair bit of memory, and I will likely run a virtual box. This will be a development machine, no video or photo editing of any sort.
Quick update, I decided to go with the MBP retina (8 GB ram, 256 GB SSD).
I ran a bench mark on my Windows machine, I ran every single application I could think of using:
Eclipse (2 instances), iTunes, 2 virtual machines, Firefox with 20 tabs, IE, Microsoft Word, etc, and I only got up to 4 GB RAM.
Still getting used to my new mac, in the process of setting up my development environment