Microsoft Watch from Mary Jo Foley notes The Downside of Embedding RSS in Longhorn. “Microsoft watchers are thinking through the security implications of Microsoft’s plan to embed RSS in Longhorn.”
The upside is that Microsoft bundling a feature in with their OS means that developers can count on the feature being available (although uptake of recent versions of windows may mean that’s only 20% of all Windows users). The downside is that it means malicious developers can count on it being available. While Microsoft is getting better at shipping software less exposed to exploit, it still enlarged the exposed surface for exploit.