I've never been much of a Mitt-fan, so I can't claim I'm heart-broken by his departure. However, I am much less of a McCain-fan, so I would have voted for him on Super Tuesday had this not been Arizona. McCain was going to win Arizona no matter what. My gripe about Mitt seems largely to be that he appeared to be running for CEO-in-Chief.
Angler in the comments to Slublog's piece over at Ace's Place makes a good point that Romney's departure puts pressure on Huckabee to shit-or-get-off-the-pot. All that said, Romney's announcement that he was dropping out of the race was handled with a grace that is hard to imagine coming from McCain. It will be interesting to see how McCain handles this Manna-from-Heaven. Does he arrogantly maintain the Maverick persona or does he truly try to move towards the conservatives who revile him so?
Couple this with the impending brokered convention on the Democrat side, and this will be a very interesting campaign.