If the Konfabulator crew hadn't merged with Yahoo! they'd be tearing their hair out. Google, while beefing up the Google Desktop app, has added Google Sidebar: "a panel on your desktop which provides convenient, one-glance access to all sorts of personalized information." Said Sidebar has a developer's API to leverage the long tail of free coder time.
A quick scan of the Google Desktop dev docs indicates all sorts of COM interfacing bits, with nasty, pointy sharp teeth. +1 for Konfabulator.