This post from November of last year by Paul Kedrosky seems especially prescient in light of recent announcements about Google Gears enabling off-line usage of Reader (for starts) and now RealNetworks making an "offline" capability announcement.  Here’s Robert Scoble’s take on that.

I worked with a really bright software architect a while ago named Philip who once told me that computing runs in cycles – everything centralizes, then decentralizes, then centralizes, and so on.  Mainframes (centralize), client/server (decentralize), internet (centralize).  Now here we are with decentralization back to the client.