SEARCH of articles
Add a search feature that looks into article titles and text.
When searching in Google Reader within a specific feed, it shows occurrences of the search phrase even within old articles that haven't been synced or read before.
HTC's News app has an instant search (similar to the instant search of google.com) that looks through synced articles (only).
A combination of the two would be great. Instant progressive search upon typing the search phrase and a thorough search of older articles that havent been synced upon hitting the enter key.