Your question is a little bit too generic. Can you please elaborate a little more? There are plenty of areas that SonarQube can be improved and one thing I'm sure of: The SonarQube guys are continuously working towards that direction. Their roadmap is really awesome : http://www.sonarqube.org/roadmap/
I've actually been fairly vocal on that topic on the user mailing list
Most of my urgent wants have been addressed, one way or another. For instance, there was a time when I really wanted more granular permissioning - e.g. the ability to control who can mark a false positive, who can change the severity of an issue. One of those is actually on the way (I forget which - it's been a while) but really, the fire has died. It turns out that it just wasn't that big an issue. Chalk one for the wisdom of the SonarSource folks. :-)
The ability to light up references within a single file is cool. I'm eager to see it expanded across files. That was on the Road Map for a while but has dropped off.
Roban Bieber wrote:We have listed our favorite plugins but what is missing that would make the program even better?
Hmm... My guess would be contributors. Whether it's to the main project, or authoring new plug-ins, or even just helping people learn about SonarQube and how to use it effectively, I'd say it needs more contributors.
That may have sounded facetious, but I do think most open source programs can always use folks to help make them better.
SCJP, SCJD, SCEA 5 "Any sufficiently analyzed magic is indistinguishable from science!" Agatha Heterodyne (Girl Genius)