If the original crowdfunding campaign was to be believed, we would have been playing Star Citizen in its 'final form' a long time ago. Sure, it would have been vastly different to their current vision, but we likely wouldn't still be thinking about it. Now, Cloud Imperium Games has released a roadmap of sorts so we can follow their regularly missed dates.
Though you should never take these kinds of things to heart with game development being a difficult beast to tackle, the roadmap should at least give an idea of how long we could be waiting.
"...will ALWAYS extend timelines or re-do features and content if we do not feel they are up to our standards" say Cloud Imperium Games. And that certainly rings true after the single-player module delay from a few weeks back. Eventually they'll get the game out of the door, but it might be some time.
The extensive list of roadmap graphics lists quite a few segments of the Star Marine module being at, or near, completion. Both animations and code are listed as 'feature complete' with combat signals being ready for QA testing.
There's an awful lot of information to decipher from the charts, so it's best you head on over to the official website for the complete explanation.