First, in one sense (but doesn't really answer your question) ... the old protocols like RSS (feeds), NNTP (news), IRC (chat), etc are never going to be "dead" because somebody somewhere will always be providing it and somebody somewhere will always be consuming it. Just like horse & buggies are not truly "dead" because a few are being run for tourists and the Amish communities, there are some old dialup BBS's serving callers with old modems even though the internet+web has supplanted it.
I think the longer form of your question for productive discussion is this: Is RSS usage decline possible to reverse with new clients on the web & mobile?
The answer is no. RSS/NNTP/IRC don't have the incentives (both economic and social) that allow them to experience a renaissance. E.g. StackOverflow may someday be supplanted by another Q&A site but it won't be supplanted by NNTP news forums. Same with RSS. Typical mass consumers use Facebook as their "rss" reader. It won't matter what kind of new RSS reader you develop, the typical web surfers don't want to manage RSS feeds.
[0] to the replies below about why "dead" often triggers unproductive arguments:
In observing decades of debates on USENET,BBSs,web, etc... the word "dead" has 2 very different meanings which needlessly causes participants to talk right past each other.
meaning #1: "dead" is harmless synonym for "decline", "losing popularity", "no longer supported", "no longer in mainstream use", etc.
meaning #2: "dead" is provocative synonym for "no longer worth learning", "useless", "stopped working forever", "nobody intelligent is using it", etc.
The amazing phenomenon that happens with asking "Is X Dead?" is that the question asker is almost always innocently using meaning #1 but the most enthusiastic answerers are using meaning #2. This is why "dead" triggers unproductive threads because both sides are talking past each other with different semantics of "dead".