Could you explain the reasoning for the cap change? I only ask to learn. I pretty much pulled the parts list from the ardweeny, so your suggestion makes me wonder.... why oh why? 
If the MCU is destined for it's own board, I would most certainly add onboard regulation. However, if it is just part of a larger board (say a led matrix with half a dozen ic's, resistors, etc, etc.) Would I be better off with multiple power supplies (possibly driven from a single input) or would a single regulated supply (of sufficient current) be suitable?
(mental side track: assuming a single power supply, would the use of optocouplers (or similar) be required to keep things "separate"? As I have said, I am just getting into electronics from 15 years in I.T. so while I know the barebones basics (120v hurts, 220v hurts even more, etc ;)), I am pretty much a blank slate and love to know the why behind how things work, not just... Thats just the way it is...)
Thanks to everyone for your help in this thread, not to mention the rest of the board!
Nick