Having an RSS reader is nice, but it strikes me that it should also be able to subscribe to podcasts and videocasts as well. The basice idea, then, is that you should be able to subscribe to a "resource" (be it text, video, or audio) in one, centralized application. Contrast this with the one-gui-application-for-every-resource setup we have, where you need to check 2 or 3 applications to keep up to date.
The media playback can be done via the appropriate utility, e.g. by embedded browser for HTML, or gstreamer for video/audio, or even by launching the appropriate application. The core problem is management and overview of media subscriptions.
As a second phase, due ot the limitations inherent in a small device such as the Nokia devices, would be to allow users to proxy their subscriptions through a Nokia/Maemo (as part of an online subscription offering, perhaps) which would transcode the video and audio to a format which will fit better on the device. With such a subscription, it would be possible to decrease the overhead (since many users likely listen/watch the many of the same things), provide Nokia/Maemo-specific offerings, and perhaps even store all but one or two of the items per subscription on the server.
