I don't know if that's a jab at Prime Fed Force, or the actual Prime games, with, since the west is who at this point really cares about Metroid still compared to the east, technically, yes, the fans do want more of the 1st person kind of Metroid games, before also the 2D ones as well, to continue the plot of Metroid Fusion.
To be honest, this whole thing is really in a bad situation... There is one issue that Metroid has in general: It technically has an ending...
Metroid Fusion technically, in a chronological sense is the last game in the timeline (what with the Metroids pretty much being definitely history at this point, and Samus with a new suit). That is especially an issue. Either two things have to happen when a new title is made:
1. They make titles that take place before this title, in between other entries in the franchise (and obviously they can only do this for so long.)
2. They retcon Fusion completely, and provide a more clean slate for future titles.
Anyway, at the moment, in a sense the series is seperated into two parts. The classic series and the Prime series (Which I guess isn't as bad as Sonic, which is divided into like 20 different styles XD)
The issue in general is the fact Metroid titles tend to develop slowly in general... I mean it's not the first time Metroid has gone through an entire console without a title.. (Looking at you N64... -_-). Due to this, it's definitely not a surprise fans would get impatient.. (especially with some other franchises dishing out at a faster rate)
Anyways all that aside.. God forbid the next Prime title ends up not meeting peoples expectations, otherwise fans will REALLY lose their marbles XD