I'm hoping they bought AppFog for the right reasons, because they want to add resources to accelerate it's market share (and of course profit). This would be good for us and PAAS in general.
But if they just bought it so they can play around with "cloud" and seem hip and cool to shareholders then let it wither on the vine, we all lose a little.
PAAS is where we're going next, any many already have. AppFog has done a great job of pushing out features and keeping the community competitive.