While i'm glad to have those other series and enjoy them, I find it a little dissapointing how badly Voyager seems to be treated, there was a massive gap between Spirit Walk to the second relaunch series, which featured four novels then also ended.
As others have said, the current VGR novel line by Kirsten Beyer has not ended, and it's been quite popular.
The gap happened for a variety of reasons. Christie Golden moved on from doing Trek, and there was some reshuffling editorially. Marco Palmieri, then the senior editor of Trek/tie-in novels at Pocket, took over as editor of VGR and began developing a new direction for the series with Kirsten Beyer, and they needed some time to work out where to go with it. Then the Destiny
trilogy event was developed and it was decided that the VGR novels would have to take it into account and coordinate with it, leading to a further postponement.
But the VGR novels have been going strong ever since, as much as any of the other 24th-century books in the past few yeras.